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Progress towards quieter civil helicopters

Published online by Cambridge University Press:  04 July 2016

M.V. Lowson
M.V. Lowson*
Affiliation:
Department of Aerospace Engineering University of Bristol
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Abstract

A review of recent developments in helicopter noise reduction is presented. The paper includes a discussion of the present state of understanding of helicopter noise radiation mechanisms and a review of actual noise reductions achieved by the manufacturers over the past decade. An analysis of progress achieved in meeting certification limits is given, together with an evaluation of the impact on design. Future trends in helicopter noise reduction based on current noise research programmes are discussed and suggestions advanced for possible additional areas of study.

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Type
Research Article
Information
The Aeronautical Journal , Volume 96 , Issue 956 , July 1992 , pp. 209 - 223
Copyright
Copyright © Royal Aeronautical Society 1992 

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References

1. Lowson, M.V. Helicopter Noise: Analysis Prediction and Methods of Reduction. AGARD Report LS-63, 1973.Google Scholar
2. Georgea, .R. Helicopter noise - state of the art, J Aircraft, 1978,15, (11), pp 707–715.Google Scholar
3. Janakiram, R.D. Aeroacoustics of Rotorcraft in AGARD Report 781, Aerodynamics'of Rotorcraft, 1990.Google Scholar
4. Cox, C.R. Flying Neighborly - How to Operate the Light/Medium Helicopter more Quietly. Bell Helicopters Textron Brochure, 1971.Google Scholar
5. Cox, C.R. Development of piloting techniques to reduce helicopter approach noise, 40th Annual Forum of the American Helicopter Society, Arlington, VA, 1984.Google Scholar
6. Childress, .O. Jr National rotorcraft noise reduction program overview, NATO-CCMS Symposium on Noise Aspects of Rotary Wing Aircraft, Monterey, 1991.Google Scholar
7. Sternfeld, H. Jr NASA/AHS rotorcraft noise reduction program: Boeing Helicopter achievements, Vertiflite, September/October 1988, pp 86–93.Google Scholar
8. Janakiram, R.D. NASA/AHS rotorcraft noise reduction program: McDonnell Douglas Company achievements, Vertiflite, November/December 1988, pp 64–68.Google Scholar
9. Shenoy, R.K. NASA/AHS rotorcraft noise reduction program: accomplishments at Sikorsky Aircraft, Vertiflite, January/February 1989, pp 68–73.Google Scholar
10. Martin, R.M. NASA/AHS rotorcraft noise reduction program: NASA Langley Acoustics Division contributions, Vertiflite, May/June 1989, pp 48–52.Google Scholar
11. Kloppel, V. Helicopter and tilt rotor exterior noise research, presented at EC BRITE-EURAM Aeronautics Meeting, 1991.Google Scholar
12. Pike, A.C. Helicopter noise certification, Applied Acoustics, 1988, 23, pp 213–230.Google Scholar
13. Kinsler, C.E. and Frey, A.R. Fundamentals of Acoustics 2nd Ed John Wiley, 1967.Google Scholar
14. Kryter, K.D. The Effects of Noise on Man Academic Press, 1970.Google Scholar
15. Ollerhead, J.B. Laboratory Studies of scales for Measuring Helicopter Noise, NASA CR 3485 3610, 1982.Google Scholar
16. Lighthill, M.J. On sound generated aerodynamically - 1: general theory, Proc R Soc, 1952, A211, pp 564–587.Google Scholar
17. Ffowcs williams, J.E. and Hawkings, D.L. Sound generation by turbulence and surfaces in arbitrary motion, Phil Trans R Soc, 1969, A264, pp 321–342.Google Scholar
18. Crows, C. Aerodynamic sound emission as a singular perturbation problem, Studies in Applied Mathematics, 1970, 49, (1), pp 21–44.Google Scholar
19. Obermeier, F. On a new representation of aeroacoustic source distribution, Acustica, 1979, 42, pp 57–71.Google Scholar
20. Hilton, W.F. Photography of airscrew sound waves, Proc R Soc, 1938, A169, pp 174–190.Google Scholar
21. Tangler, J.L. Schlieren and noise studies of rotors in forward flight, Paper at 33rd Annual Forum of the American Helicopter Society, 1977.Google Scholar
22. Schmitz, F.H. and Yu, Y.H. Helicopter impulsive noise: theoretical and experimental status, J Sound Vib 1986, 109, Pt 3, pp 361–422.Google Scholar
23. Lowson, M.V.,Byham, G.,Perry, .F.J., and Hawkings, D.L. Rotor Tip, British Patent 1538055, US patent 4077741, etc, 1976.Google Scholar
24. Perry, F.J. Aerodynamics of the helicopter world speed record, Proceedings of 43rd Forum of the American Helicopter Society, 1987.Google Scholar
25. Lowson, M.V. and Balmford, D.E.H. Future advanced technology rotorcraft, Aeronaut J, February 1980, pp 39–49.Google Scholar
26. Pike, A.C. Flight Evaluation of the Acoustic Characteristics of Lynx Main Rotor Blades, WHL RP 748, 1989.Google Scholar
27. Leverton, J.W. Twenty five years of rotorcraft aeroacoustics: historical perspective and important issues, J Sound Vib, 1989, pp 261–287.Google Scholar
28. Cox, C.R. Helicopter Rotor Aerodynamic and Aeroacoustic Environments, AIAA 77-1388, 1977.Google Scholar
29. Martin, R.M., Marcolini, M.A., Splettstoesser, W.R., and Schultz, K.-J. Wake Geometry Effects on Rotor Blade-Vortex Interaction Noise Directivity, NASA Technical Paper 3015, 1990.Google Scholar
30. Scully, M.P. A Method for Computing Helicopter Wake Distortion, MIT Aeroelastic and Structures Lab Report TR 138-1, 1967.Google Scholar
31. Batchelor, G.K. An Introduction to Fluid Dynamics, Cambridge University Press, 1967.Google Scholar
32. Beddoes, T.S. Unsteady aerodynamics application to helicopter noise and vibration sources, AGARD Symposium on Unsteady Aerodynamics, Gottingen, May 1985.Google Scholar
33. Beddoes, T.S. Two and three dimensional indicial methods for rotor dynamic airloads, AHS Meeting on Rotorcraft Dynamics, Arlington,Texas, 1989.Google Scholar
34. Pike, A.C. Application of high resolution airload calculations to helicopter noise prediction, AHS National Specialists Meeting Arlington Texas, 1987.Google Scholar
35. Obermeier, F. Numerical and experimental investigations on aerodynamic sound generation due to transonic vortex-rotor-interaction, NATO-CCMS Symposium on Noise Aspects of Rotary Wing Aircraft, Monterey, 1991.Google Scholar
36. Meier, G.E., Schievelbusch, U and Lent, H.-M. Stosswellenentstehung bei transsoninaher Wirbel-Profil-Wechselwirkung, Z Flugwiss-Weltraumfornah, 1990,14, pp 327–332.Google Scholar
37. Lent, H., Lohr, K., Meier, G., Miller, K., Schievelbusch, U., Schurmann, O., and Szumowski, A. Noise Mechanisms of Transonic Vortex Airfoil Interaction, AIAA-90-3972, 1990.Google Scholar
38. Tudeman, H. Investigations of Transonic Flow Around Oscillating Aerofoils, NLR Rep 77090-U, 1977.Google Scholar
39. Lyrintzis, A.S. and George, A.R. Far field noise of transonic blade- vortex interactions, J Am Helicopter Soc, 1989, 34, (3), pp 30–39.Google Scholar
40. Lowson, M.V. and Ollerhead, J.B. Studies of Helicopter Rotor Noise, USAAVLABS Technical Report 68–60, 1968.Google Scholar
41. Widnall, S.E. Helicopter noise due to blade-vortex interaction, J Acoust Soc Am, 1971, 50, (1), pp 354–365.Google Scholar
42. George, A.R., and Chang, S.B. Flow Field and Acoustics of Two-Dimensional Transonic Blade-Vortex Interactions, AIAA Paper 84-2309, 1984.Google Scholar
43. Streby, O. and Marze, H.J. Prediction and reduction of helicopter external noise at Aerospatiale Helicopter Division, NATO-CCMS Symposium on Noise Aspects of Rotary Wing Aircraft, Monterey, 1991.Google Scholar
44. Brooks, T.F., Booth, E.R., Jolly, J.R. Jr, Yeager, W.T. and Wilbur, M.L. Reduction of blade-vortex interaction noise through higher harmonic pitch control, J American Helicopter Society, 1990, pp 86–91.Google Scholar
45. Splettstoesser, W.R., Lehmann, G. and van der Wall, B. Higher harmonic control of a model helicopter rotor to reduce blade vortex interaction noise, Z Flugwiss Weltraumforch, 1990, 14, pp 109–116.Google Scholar
46. Brooks, T.F., Booth, E.R., Splettstoesser, W., Schultz, K.-J., Kube, R., Niesl, G. and Streby, O. Results of a higher harmonic control acoustic experiment in the DNW to reduce rotor BVI impulsive noise, NATO-CCMS Symposium on Noise Aspects of Rotary Wing Aircraft, Monterey, 1991.Google Scholar
47. Hardin, J.C. and Lamkin, S.L. Concepts for reduction of blade/vortex interaction noise, J Aircraft, 1987, 24, (2), pp 120–125.Google Scholar
48. Brooks, T.F. and Schlinker, R.H. Progress in rotor broad band noise research, Vertica , 1983, 7, (4), pp 287–307.Google Scholar
49. George, A.R. and Chou, S.-T. Comparison of broad band noise mechanisms, analyses and experiments on rotors, J Aircraft, 21, (8), pp 583–592.Google Scholar
50. Leverton, J.W. Noise of Rotorcraft, Westland Helicopters RP 365, 1969.Google Scholar
51. Homicz, G.F. and George, A.R. Broadband and dinarete frequency radiation from subsonic rotors, J Sound Vib, 1974, 36, pp 151–177.Google Scholar
52. Simonich, J.C, Amiet, R.K., Schlinker, R.H. and Greitzer, E.M. Helicopter Rotor Noise Due to Ingestion of Atmospheric Turbulence, NASA CR 3973, (1986).Google Scholar
53. Simonich, J.C, Schlinker, R.H. and Amiet, R.K. Experimental as sessment of a turbulence ingestion noise theory, 44th AHS Forum, 1988.Google Scholar
54. Brooks, T.F., Marcouni, M.A. and Pope, D.S. Main rotor broad band noise study in the DNW, J Am Helicopter Soc, 1989, 34, (2), pp 3–12.Google Scholar
55. Brooks, T.F., Jolly, J.R. Jr and Marcolini, M.A. Helicopter Main Rotor Noise; Determination of Source Contributions Using Scale Model Data, NASA Technical Paper 2825, 1988.Google Scholar
56. Ffowcs williams, J.E. and Hall, L.H. Aerodynamic sound generation by turbulent flow in the vicinity of a scattering half-plane J Fluid Mech, 1970, 40, pp 657–670.Google Scholar
57. Howe, M.S. A review of the theory of trailing edge noise J Sound Vib, 1978, 61, (3), pp 437–465.Google Scholar
58. Brooks, T.F., Pope, D.S. and Marcolini, M.A. Airfoil Self Noise and Prediction, NASA Reference Publication 1218, 1989.Google Scholar
59. Schlinker, R.H. and Amiet, R.K. Helicopter Rotor Trailing Edge Noise, NASA CR 3470, 1981, see also AIAA Paper 81-2001.Google Scholar
60. Brooks, T.F., and Marcolini, M.A. Airfoil tip vortex formation noise AIAA J, 1986, 24, (2), pp 246–252.Google Scholar
61. Lowson, M.V., Whatmore, A.R. and Whitfield, C.E. Source Mechanisms for Rotor Noise Radiation, NASA CR 2077, 1973.Google Scholar
62. Paterson, R.W., Vogt, P.G., Fink, M.R. and Munch, C.L. Vortex noise of isolated airfoils, J Aircraft, 1973, 10, (5), pp 296–302.Google Scholar
63. Brooks, T.F. and Hodgson, T.H. Trailing edge noise prediction using measured surface pressures, J Sound Vib, 1981, 78, (1), pp 69–117.Google Scholar
64. Grosveld, F.W. Prediction of broad band noise from horizontal axis wind turbines, J .Propulsion, 1985, 1, (4), pp 292–299.Google Scholar
65. George, A.R. and Chou, S.-T. A comparative study of tail rotor noise mechanisms, J Am Helicopter Soc, 1986, pp 36–42.Google Scholar
66. Tadghiohi, H. An Analytical Model for Prediction of Main Rotor/Tail Rotor Interaction Noise, AIAA paper 89-1130,1989.Google Scholar
67. Leverton, J.W. Reduction of helicopter noise by the use of a quiet tail rotor, Vertica, 1982, 6, pp 37–47.Google Scholar
68. Pike, A.C. and Dickens, J.R.F. Helicopter External Noise Predictions Phase 2, Westland Helicopters RP 654, 1982.Google Scholar
69. Succi, G.P. and Brieger, J.T. Prediction of helicopter rotor noise from measured blade surface pressures, 37th Annual Forum of the AHS, 1981.Google Scholar
70. Visintainer, J.A., Burley, C.L., Marcolini, M.A. and Liu, S.R. Acoustic predictions using measured pressures from a model rotor in the DNW, Proceedings of 47th Forum of the American Helicopter Society, 1991.Google Scholar
71. Lowson, M.V. and Ollerhead, J.B. A theoretical study of helicopter rotor noise, J Sound Vib, 1969, 9, pp 197–222,Google Scholar
72. Damongeot, A., d'Ambra, F. and Masure, B. Towards a better understanding of helicopter external noise, Proceedings of the 39th Annual Forum of the American Helicopter Society, 1983, pp 445–457.Google Scholar
73. Janakiram, R.D., Smith, M.J. and Tadghighi, H. Importance of Engine as a Source of Helicopter External Noise, AIAA Paper 89-1147,1989.Google Scholar
74. Perry, F.J., and Pike, A.C. Helicopter rotor design for noise constraints and developments in the prediction of rotor noise sources at Westland Helicopters Ltd, NATO-CCMS Pilot Study on AircraftNoise, Williamsburg Virginia, 1988.Google Scholar
75. Balmford, D.E.H. and Benger, B.S. The compound helicopter - a concept revisited, Paper ERF 91-07, 17th European Rotorcraft Forum, 1991.Google Scholar
76. Leverton, J.W. EH101 advance technology rotorcraft: designed for low noise, Applied Acoustics, 1991,32, pp 13–22.Google Scholar
77. Sternfield, H. Jr and Alexander, H. Technical design issues intilt rotor acoustics, NATO-CCMS Symposium on Noise Aspects of Rotary Wing Aircraft, Monterey, 1991.Google Scholar
78. Cox, C.L. Tilt rotor noise, NATO-CCMS Symposium on Noise Aspects of Rotary Wing Aircraft, Monterey, 1991.Google Scholar
79. Baeder, J. Euler solutions to nonlinear acoustics of non-lifting rotor blades in forward flight, AHS/RAeS meeting on Rotorcraft Acoustics, Philadelphia, 1991.Google Scholar
80. Lowson, M.V., Fiddes, S.P. and Aston, J.A.G. Theoretical Modelling of Helicopter Noise Radiation, University of Bristol Report BU/AERO/419, 1990.Google Scholar
81. Norman, .T.R. and Light, J.S. Rotor tip vortex geometry measurements using the wide-field shadowgraph technique, J Am Helicopter Soc, April 1987, pp 40–50.Google Scholar
82. Kerschen, E. and Tsai, C. Influence of Airfoil Thickness on Convected-Gust Interaction Noise, AIAA 89-1082 1989.Google Scholar
83. Tsai, C. and Kerschen, E. Influence of Airfoil Nose Radius on Sound Radiated by Gust Interactions, AIAA 90-3912,1990.Google Scholar