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Evaluation of the feasibility of scale modeling to quantify wind and terrain effects on low-angle sound propagationThe feasibility of acoustical scale modeling techniques for modeling wind effects on long range, low frequency outdoor sound propagation was evaluated. Upwind and downwind propagation was studied in 1/100 scale for flat ground and simple hills with both rigid and finite ground impedance over a full scale frequency range from 20 to 500 Hz. Results are presented as 1/3-octave frequency spectra of differences in propagation loss between the case studied and a free-field condition. Selected sets of these results were compared with validated analytical models for propagation loss, when such models were available. When they were not, results were compared with predictions from approximate models developed. Comparisons were encouraging in many cases considering the approximations involved in both the physical modeling and analysis methods. Of particular importance was the favorable comparison between theory and experiment for propagation over soft ground.
Document ID
19860005586
Acquisition Source
Legacy CDMS
Document Type
Contractor Report (CR)
Authors
Anderson, G. S. (Bolt, Beranek, and Newman, Inc. Cambridge, MA, United States)
Hayden, R. E. (Bolt, Beranek, and Newman, Inc. Cambridge, MA, United States)
Thompson, A. R. (Bolt, Beranek, and Newman, Inc. Cambridge, MA, United States)
Madden, R. (Bolt, Beranek, and Newman, Inc. Cambridge, MA, United States)
Date Acquired
September 5, 2013
Publication Date
January 1, 1985
Subject Category
Acoustics
Report/Patent Number
NASA-CR-172488
BBN-5516
NAS 1.26:172488
Accession Number
86N15056
Funding Number(s)
CONTRACT_GRANT: NAS1-16521
PROJECT: RTOP 505-33-90-02
Distribution Limits
Public
Copyright
Work of the US Gov. Public Use Permitted.

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