The effect of angle-of-attack or sideslip on noise radiation by a propeller is considered, (Fig. 3). For a single propeller, neglecting installation effects, the angles of attack and sideslip can be combined (Fig. 2). The simplest model of the propeller, as a point multipole source, leads to an effect of inflow angle on acoustic radiation intensity, which is specified by the Doppler factor (Fig. 1). This simple model gives results consistent with experiments (Zandbergen, Sarin & Donnely, 1984, 1990), with a scaled propeller in a wind tunnel; the simple alberaic formula (Section 2), gives better results than a more elaborate numerical method (Succi, 1979). Proceeding to consider finite source distributions along the blades, leads to a less simple analytical theory (Section 3), based on radiation integrals valid in the far-field. It allows the consideration of unsteady monopole, dipole and quadrupole sources. This analytical theory, allowing for a distribution of acoustic sources along the span of the blades, gives a non-negligible correction to the algebraic theory. Thus the latter is adequate only as a simple order-of-magnitude estimate of noise level; a more acurate calculation noise levels requires evaluation of the radiation integrals, based on a knowledge of the acoustic source distribution.

1.
Abramowitz, M., and Stegun, I., 1964, Handbook of Mathematical Functions, Dover.
2.
Campos, L. M. B. C., 1978a, “On the Emission of Sound by an Ionized Inhomogeneity,” Proc. Roy. Soc. A351, pp. 65–91.
3.
Campos
L. M. B. C.
,
1978
b, “
On the Spectral Broadening of Sound by Turbulent Shear Layers
,”
J. Fluid Mech.
, Vol.
89
, pp.
723
783
.
4.
Campos
L. M. B. C.
,
1986
, “
On Waves in Gases. Part I; Acoustics of Jets, Turbulence and Ducts
,”
Rev. Mod. Phys.
, Vol.
56
, pp.
217
282
.
5.
Canard, S., and Carvana, D., 1994, “Propeller Thickness and Loading Noise Prediction Taking into Account Incidence Angle; Far-field Approximation,” ON-ERA/SNAAP report.
6.
Dahan
C.
,
Avezard
G.
,
Guillien
G.
,
Malarmey
C.
, and
Chombart
J.
,
1981
, “
Propeller Light Aircraft Noise at Discrete Frequencies
,”
AIAA J. of Aircraft
, Vol.
18
, pp.
480
486
.
7.
Envia, E., 1991, “Prediction of Noise of a Propfan at Angle of Attack,” NASA CR-189047.
8.
Envia
E.
,
1994
, “
Asymptotic Theory of Supersonic Propeller Noise
,”
AIAA Journ.
, Vol.
32
, pp.
239
246
.
9.
Farassat, F., 1975, “Theory of Noise Generation from Moving Bodies with an Application to Helicopter Rotors,” NASA TR-451.
10.
Farassat
F.
,
1981
, “
Linear Acoustic Formulas for the Calculation of Rotating Blade Noise
,”
AIAA Journ.
, Vol.
19
, pp.
1122
1130
.
11.
Farassat
F.
, and
Succi
G. P.
,
1980
, “
A Review of Propeller Discrete Frequency Noise Prediction Technology with Emphasis on Two Current Methods of Time Domain Calculations
,”
J. Sound Vib.
, Vol.
71
, pp.
399
342
.
12.
Ffowcs-Williams, J. E., and Hawkins, D. L., 1968, “Sound Generation by Turbulence and Surfaces in Arbitrary Motion,” Phil. Trans. Roy. Soc., A264, pp. 321–342.
13.
Glauert, H., 1936, Airfoil and Airscrew Theory, Cambridge U.P.
14.
Goldstein
M. E.
,
1974
, “
Unified Approach to Aerodynamic Sound Generation in the Presence of Solid Boundaries
,”
J. Acoust. Soc. Am.
, Vol.
56
, pp.
497
506
.
15.
Goldstein, M. E., 1976 Aeroacoustics, McGraw-Hill.
16.
Gounet
H.
, and
Lewy
S.
,
1988
, “
Prediction of Prop-fan Noise by a Frequency-domain Scheme
,”
AIAA J. Aircraft
, Vol.
25
, pp.
428
435
.
17.
Gutin, L. Ya., 1936, “On the Sound Field of a Rotating Propeller,” NASA TM-1195 (1948).
18.
Hanson
D. B.
,
1980
a, “
Helicoidal Surface Theory for Harmonic Noise of Propellers in the Far-field
,”
AIAA Journ.
, Vol.
18
, pp.
1213
1220
.
19.
Hanson
D. B.
,
1980
b, “
Influence of Propeller Design Parameters on Far-field Harmonic Noise in Forward Flight
,”
AIAA Journ.
, Vol.
18
, pp.
1313
1319
.
20.
Hanson
D. B.
,
1983
, “
Compressible Helicoidal Surface Theory for Propeller Aerodynamics and Noise
,”
AIAA Journ.
, Vol.
21
, pp.
881
889
.
21.
Hanson
D. B.
,
1985
, “
Noise of Counterrotation Propellers
,”
AIAA Journ. of Aircraft
, Vol.
22
, pp.
609
617
.
22.
Hubbard, H. H., 1948, “Sound from Dual-rotating and Multiple Single Rotating Propellers,” NASA TM-I654.
23.
Jou
W. H.
,
1989
, “
Supersonic Propeller Noise in a Uniform Flow
,”
AIAA Journ.
, Vol.
27
, pp.
385
390
.
24.
Kreijsa, E. A., 1990, “Prediction of the Noise from a Propeller at Angle of Attack,” AIAA Paper 90-3954, 13th Aeroacoustics Conference, Tallahassee.
25.
Landau, L. D., and Lifshitz, E. F., 1953, Fluid Dynamics, Pergamon.
26.
Lighthill, M. J., 1952, “On Sound Generated Aerodynamically. I: Turbulence as a Source of Sound,” Proc. Roy. Soc. A211, pp. 564–587.
27.
Lighthill, M. J., 1978, Waves in Fluids, Cambridge U.P.
28.
Mani, R., 1990, “The Radiation of Sound from a Propeller at Angle of Attack,” NASA CR-4264.
29.
Parry, A. B., and Crighton, D. G., 1986, “Theoretical Prediction of Single Rotation Propeller Noise,” AIAA Paper 86-1891, 10th Aeroacoustics Conference, Seattle.
30.
Schulten, J. B. H. M., 1987, “A Spectral Method for the Computation of Propeller Acoustics,” AIAA Paper 87-2674, 11th Aeroacoustics Conf., Palo Alto.
31.
Schulten
J. B. H. M.
,
1988
, “
Frequency-domain Method for the Computation of Propeller Acoustics
,”
AIAA Journ.
, Vol.
26
, pp.
1027
1035
.
32.
Stuff
R.
,
1988
, “
Noise Field of a Propeller with Angular Inflow
,”
AIAA Journ.
, Vol.
26
, pp.
777
782
.
33.
Succi, G. P., 1979, “Design of Quiet Efficient Propellers,” Society of Automotive Engineers, Paper 790584.
34.
Tam
C. K. W.
, and
Salikuddin
M.
,
1986
, “
Weakly Non-linear Acoustic and Shock Wave Theory of the Noise of Advanced High-speed Turbopropellers
,”
J. Fluid Mech.
, Vol.
164
, pp.
127
154
.
35.
Tam
C. K. W.
,
Salikuddin
M.
, and
Hanson
D. B.
,
1988
, “
Acoustic Interference of Counter-rotation Propellers
,”
J. Sound Vib.
, Vol.
124
, pp.
357
366
.
36.
Zandbergen, T., Sarin, S. L., and Donelly, R. P., 1984, “Propeller Noise Measurements in DNW on the Fuselage of a Twin Engine Aircraft Model,” AIAA Paper 84-2367, 9th Aeroacoustics Conf., Williamsburg.
37.
Zandbergen, T., Sarin, S. L., and Donelly, R. P., 1990, “Experimental/Theoretical Investigation of the Sound Field of an Isolated Propeller, Including Incidence Effects,” AIAA Paper 90-3952, 13th Aeroacoustics Conf. Tallahassee.
This content is only available via PDF.
You do not currently have access to this content.