1、_ SAE Technical Standards Board Rules provide that: “This report is published by SAE to advance the state of technical and engineering sciences. The use of this report is entirely voluntary, and its applicability and suitability for any particular use, including any patent infringement arising there
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3、ublication may be reproduced, stored in a retrieval system or transmitted, in any form or by any means, electronic, mechanical, photocopying, recording, or otherwise, without the prior written permission of SAE. TO PLACE A DOCUMENT ORDER: Tel: 877-606-7323 (inside USA and Canada) Tel: +1 724-776-497
4、0 (outside USA) Fax: 724-776-0790 Email: CustomerServicesae.org SAE WEB ADDRESS: http:/www.sae.org SAE values your input. To provide feedback on this Technical Report, please visit http:/www.sae.org/technical/standards/ARP5534 AEROSPACE RECOMMENDED PRACTICE ARP5534 Issued 2013-08 Application of Pure
5、-Tone Atmospheric Absorption Losses to One-Third Octave-Band Data RATIONALE Atmospheric absorption is an important component of acoustic propagation between a source and receiver. This ARP overviews an updated methodology to calculate atmospheric absorption consistent with current scientific informa
6、tion. FOREWORD The United States Department of Transportation, John A. Volpe National Transportation Systems Center (Volpe Center) Environmental Measurement and Modeling Division, in support of the Federal Aviation Administrations (FAA) Office of Environment and Energy (AEE), and working under the a
7、uspices of the Society of Automotive Engineers (SAE) Project Working Team (PWT), has developed a method to modernize the calculation of atmospheric absorption for analysis of aircraft noise in one-third octave-bands. The preceding standard, ARP866, was issued in August 1964 and revised as ARP866A in
8、 March 1975. Based on the theory of Kneser, the laboratory results of Harris, and field data from Rolls Royce, Boeing, and Douglas, ARP866A calculates pure-tone atmospheric absorption coefficients at either the center or lower limiting frequency of a one-third octave-band to represent attenuation ov
9、er the full one-third octave-band. In contrast, this document introduces a method of calculating one-third octave-band attenuation as a function of the pure-tone attenuation at the exact mid-band frequency, over the propagation path. Two published standards - ISO 9613-1, “Acoustics - Attenuation of
10、sound during propagation outdoors - Part 1: Calculation of the absorption of sound by the atmosphere,” and ANSI S1.26-1995, “Method for Calculation of the Absorption of Sound by the Atmosphere” - are referenced repeatedly throughout this document. Each presents methods for calculating atmospheric ab
11、sorption in different types of analyses. The pure-tone absorption equations in the ISO and ANSI standards are functions of temperature, humidity, and atmospheric pressure, where those of ARP866A are functions only of temperature and humidity. The ISO and ANSI equations are arithmetically identical t
12、o one another and have been found to be more accurate than the corresponding equations of ARP866A. They are, therefore, adopted in this document. SAE INTERNATIONAL ARP5534 Page 2 of 31 Annex D of both the ISO and ANSI standards present a rigorous method of adapting the pure-tone algorithms for use i
13、n fractional-octave-band analysis called the Spectrum Integration or Exact Method. The Exact Method, as used in aircraft noise analysis, calculates atmospheric absorption over narrow-bands to find the cumulative attenuation across a one-third octave-band, accounting for filter effects. It, therefore
14、, requires detailed knowledge of both the source spectrum and filter characteristics. This requirement makes its use for some applications, including aircraft noise certification, unrealistic. Alternatively, Annex E of the ANSI standard presents an empirical method of adapting pure-tone algorithms t
15、o one-third octave-bands, known as the Approximate Method. This method avoids the need for detailed narrow-band or filter data by introducing an approximate relationship between path-length attenuation at mid-band frequencies and attenuation over full one-third octave-bands. However, its use is limi
16、ted to mid-band path-length attenuations less than 50 dB. The method described in this document (the SAE Method), retains the eased data requirements of the Approximate Method while extending its applicability to path-length attenuations greater than 50 dB. The SAE Method was designed to be consiste
17、nt with Exact Method results. It is intended to replace the absorption methodologies outlined in ARP866A. SAE INTERNATIONAL ARP5534 Page 3 of 31 TABLE OF CONTENTS 1. SCOPE 4 2. REFERENCES 4 2.1 Applicable Documents 4 2.1.1 SAE Publications . 4 2.1.2 ISO Publications 4 2.1.3 ANSI Publications . 4 2.1
18、.4 IEC Publications 4 2.1.5 JASA Publications . 5 2.1.6 INCE Publications . 5 2.1.7 ICAO Publications . 5 2.1.8 Federal Aviation Regulations 5 2.1.9 Related Publications . 5 2.1.10 Other Related Publications . 6 2.2 Definitions . 6 2.2.1 ATMOSPHERIC ABSORPTION . 6 2.2.2 PATH-LENGTH ABSORPTION 6 2.2.
19、3 EXACT METHOD 6 2.2.4 APPROXIMATE METHOD . 6 2.2.5 SAE METHOD 6 3. PROCEDURE FOR CALCULATING ATMOSPHERIC ABSORPTION 6 3.1 Pure-Tone Mid-band Attenuation Coefficient 7 3.2 One-Third Octave-Band Attenuation 8 3.2.1 Exact Method 8 3.2.2 SAE Method 8 4. LIMITATIONS 10 4.1 Atmospheric Considerations . 1
20、1 4.2 Spectrum . 11 4.3 Accuracy . 11 5. NOTES 11 APPENDIX A SENSITIVITY ANALYSIS 12 APPENDIX B SENSITIVITY ANALYSIS (IN SITU AIRCRAFT DATA) . 31 FIGURE 1 NON-TONAL TEST SPECTRA DATA SLOPES: -5, -2, 0, +5 DB PER 1/3 OCTAVE-BAND . 9 FIGURE 2 APPROXIMATE METHOD ANSI FUNCTION - APPROXIMATE METHOD PREDI
21、CTED VERSUS MID-BAND-LEVEL ATTENUATION . 10 SAE INTERNATIONAL ARP5534 Page 4 of 31 1. SCOPE This document presents a practical method for calculating atmospheric absorption for wide-band sounds analyzed with one-third octave-band filters, called the SAE Method. The SAE Method utilizes pure-tone atte
22、nuation algorithms originally published in ISO 9613-1 and ANSI S1.26-1995 to calculate path-length attenuation at mid-band frequencies. The equations introduced in this standard transform the pure-tone, mid-band attenuation to one-third octave-band attenuation. The purpose of this guidance document
23、is to extend the useful attenuation range of the Approximate Method outlined in ANSI S1.26-1995, and to replace ARP866A. Calculation of sound attenuation caused by mechanisms other than atmospheric absorption such as divergence, refraction, scattering due to turbulence, ground reflections, or non-li
24、near propagation effects, is outside the scope of this document. 2. REFERENCES 2.1 Applicable Documents The following publications form a part of this document to the extent specified herein. The latest issue of SAE publications shall apply. The applicable issue of other publications shall be the is
25、sue in effect on the date of the purchase order. In the event of conflict between the text of this document and references cited herein, the text of this document takes precedence. Nothing in this document, however, supersedes applicable laws and regulations unless a specific exemption has been obta
26、ined. 2.1.1 SAE Publications Available from SAE International, 400 Commonwealth Drive, Warrendale, PA 15096-0001, Tel: 877-606-7323 (inside USA and Canada) or 724-776-4970 (outside USA), www.sae.org. ARP866A Standard Values of Atmospheric Absorption as a Function of Temperature and Humidity 2.1.2 IS
27、O Publications Available from International Organization for Standardization, ISO Central Secretariat, 1, ch. de la Voie-Creuse, CP 56, CH-1211 Geneva 20, Switzerland, Tel: +41-22-749-01-11, www.iso.org. ISO 9613-1 Noise Acoustics - Attenuation of Sound during Propagation Outdoors - Part 1: Calculat
28、ion of the Absorption of Sound by the Atmosphere, 1993 2.1.3 ANSI Publications Available from American National Standards Institute, 25 West 43rd Street, 4th Floor, New York, NY 10036-8002, Tel: 212-642-4900, www.ansi.org. ANSI S1.26-1995 Method for Calculation of the Absorption of Sound by the Atmo
29、sphere. 2.1.4 IEC Publications Available from International Electrotechnical Commission, 3, rue de Varembe, P.O. Box 131, CH-1211 Geneva 20, Switzerland, Tel: +41-22-919-02-11, www.iec.ch. IEC 61265 Electroacoustics - Instruments for Measurement of Aircraft Noise - Performance Requirements for Syste
30、ms to Measure One-Third-Octave Band-Sound Pressure Levels in Noise Certification of Transport-Category Aeroplanes, 1995. IEC 61260 Octave-Band and Fractional-Octave-Band Filters, 1995. SAE INTERNATIONAL ARP5534 Page 5 of 31 2.1.5 JASA Publications Available from the Acoustical Society of America, ht
31、tp:/asadl.org/jasa. Kneser, H. O., “The interpretation of the anomalous sound-absorption in air and oxygen in terms of molecular collisions,” J. Acoust. Soc. Am., Vol. 5, No. 2, pp 122-126, 1933. Harris, C. M., “Absorption of sound in air in the audio-frequency range,” J. Acoust. Soc. Am., Vol. 35,
32、No. 1, pp 11-17, 1963. 2.1.6 INCE Publications Available from the Institute of Noise Control Engineering, 100 E. Washington Street, Springfield, IL 62701, Tel: 217-528-9945, www.inceusa.org. Rickley, E. J., Fleming, G. G., Roof, C. J., “Simplified procedure for computing the absorption of sound by t
33、he atmosphere,” Noise Control Eng. J., Vol. 55, No. 6, pp 482-494, 2007. Joppa, Paul D., Sutherland, Louis C., Zuckerwar, Allen J., “Representative frequency approach to the effect of bandpass filters on evaluation of sound attenuation by the atmosphere,” Noise Control Eng. J., Vol. 44, No. 6, pp 26
34、1-273, 1996. 2.1.7 ICAO Publications Available from International Civil Aviation Organization, 999 University Street, Montreal, Quebec H3C 5H7, Canada, Tel: 514-954-8219, www.icao.int. International Civil Aviation Organization, Standards and Recommended Practices, Annex 16, “Aircraft Noise,” Montrea
35、l, Quebec, Canada, January, 1972. 2.1.8 Federal Aviation Regulations Available from the Electronic Code of Federal Regulations, http:/www.ecfr.gov. Code of Federal Regulations, Title 14, Part 36, Noise Standards: Aircraft Type and Worthiness Certification, Washington, D.C.: Federal Aviation Administ
36、ration, Current Amendment. 2.1.9 Related Publications Available from the U.S. Department of Commerce, Technology Administration, National Technical Information Service (NTIS), Alexandria, VA, www.ntis.gov. Fleming, G., Roof, C., Read, D., Rapoza, A., “Evaluation of One-Third Octave-Band Filters used
37、 for Aircraft Noise Certification,” Report No. DTS-74-FA753-LR5, Cambridge, MA: John A. Volpe National Transportations Systems Center, August 1997. Rickley, E. J., Rosenbaum, J. E., Fleming, G. G., Roof, C. J., Boeker, E. R., “Development of Simplified Procedure for Computing the Absorption of Sound
38、 by the Atmosphere and Applicability to Aircraft Noise Certification: Proposed SAE Method,” Report No. DOT-VNTSC-FAA-12-14, Cambridge, MA: John A. Volpe National Transportations Systems Center, November 2012. Reherman, C. A., Roof, C. J., Fleming, G. G., “SAE ARP 866A vs. ISO 9613-1/ANSI S1.26-1995:
39、 A Sensitivity Analysis Comparing Two Procedures for Adjusting As-Measured Spectra to Reference Conditions,” Cambridge, MA: John A. Volpe National Transportations Systems Center, May 2002, NTIS # PB2003-101662. Rickley, E. J., Fleming, G. G., “Computing the Absorption of Sound by the Atmosphere and
40、its Applicability to Aircraft Noise Certification,” Cambridge, MA: John A. Volpe National Transportations Systems Center, August 1998, NTIS # PB2003-101661. SAE INTERNATIONAL ARP5534 Page 6 of 31 2.1.10 Other Related Publications The following publication is provided for information purposes only an
41、d is not a required part of this SAE Aerospace Technical Report. Coignus, Bernard, “Influence des paramtres mtorologiques sur la propagation du son travers latmosphre, application la certification,“ Technical Report 510.0141/98, Aerospatiale, Toulouse, France, March 1998 (in French). 2.2 Definitions
42、 2.2.1 ATMOSPHERIC ABSORPTION The attenuation of sound caused by propagation through the atmosphere. Atmospheric absorption includes the effects of thermal losses, shear viscosity losses, and molecular relaxation losses of oxygen and nitrogen. It is a function of frequency, temperature, relative hum
43、idity and atmospheric pressure. 2.2.2 PATH-LENGTH ABSORPTION The attenuation of sound caused by propagation through the atmosphere, over a set path-length. 2.2.3 EXACT METHOD A spectrum integration procedure used for calculating atmospheric absorption of wideband sounds analyzed by fractional-octave
44、-band filters. One-third octave-band filters are assumed in examples in Appendix A of this document. The Exact Method is described in detail in the ISO 9613-1 and ANSI S1.26-1995 standards. 2.2.4 APPROXIMATE METHOD An empirical method of calculating atmospheric absorption of wideband sounds analyzed
45、 by fractional-octave-band filters. One-third octave-band filters are assumed in examples in Appendix A of this document. Band attenuation is computed as a function of path-length absorption at the mid-band frequency. The Approximate Method is described in detail in ANSI S1.26-1995 and may be substi
46、tuted for the Exact Method, with errors less than 5%, where path-length attenuation at the exact mid-band frequency is less than 50 dB. 2.2.5 SAE METHOD An approximate method of calculating atmospheric absorption of wideband sounds analyzed by one-third octave-band filters that does not have the 50
47、dB path-length attenuation limitation of the Approximate Method. The SAE Methods performance has been investigated over one-third octave-bands from 25 Hz to 20 kHz. It is described in detail herein and is consistent with the Exact Method for mid-band path-length attenuation up to 100 dB with root me
48、an square errors less than 3%, and for mid-band attenuation up to 500 dB with root mean square errors less than 4% (Rickley et al., 2012). 3. PROCEDURE FOR CALCULATING ATMOSPHERIC ABSORPTION Section 3.1 outlines the procedure for calculating pure-tone (single frequency) attenuation coefficients for
49、selected temperature, relative humidity, and atmospheric pressure values. Section 3.2 comments briefly about the Exact Method and outlines the procedure for calculating one-third octave-band attenuation using the SAE Method. SAE INTERNATIONAL ARP5534 Page 7 of 31 3.1 Pure-Tone Mid-band Attenuation Coefficient The procedure for calculating single frequency atmospheric absorption effects is described in detail in the ISO 9613-1 a
