Acoustic power spectra due to multiple internal wave scattering

1978 ◽  
Vol 63 (S1) ◽  
pp. S23-S24 ◽  
Author(s):  
F. D. Tappert ◽  
L. B. Dozier
Keyword(s):  
Internal Wave ◽  
Wave Scattering ◽  
Power Spectra ◽  
Acoustic Power

Analytical Acoustic Power Spectrum Formulations for Rotating Monopole and Dipole Point Sources

2016 ◽  
Vol 138 (2) ◽  
Author(s):  
Yijun Mao ◽  
Chen Xu
Keyword(s):  
Power Spectrum ◽  
Power Spectra ◽  
Expansion Method ◽  
Acoustic Power ◽  
Point Sources ◽  
Harmonic Series ◽  
Dipole Source ◽  
Power Ratio ◽  
Good Agreement ◽  
Series Expansion Method

Analytical acoustic power spectrum formulations for the rotating monopole and dipole point sources are proposed by employing the spherical harmonic series expansion method. Both the analytical acoustic power spectra and the overall acoustic power show a good agreement with the results obtained from other methods. A nondimensional acoustic power ratio (APR) is employed to investigate the effects of the rotational Mach number, the direction of the dipole source, and the number of sources on the acoustic power output.

Spectral Properties and Quantitative Evaluation of Hypernasality in Vowels

1996 ◽  
Vol 33 (1) ◽  
pp. 43-50 ◽  
Author(s):  
Ryuta Kataoka ◽  
Ken-Ichi Michi ◽  
Kaoru Okabe ◽  
Tanetoshi Miura ◽  
Hiroshi Yoshida
Keyword(s):  
Spectral Properties ◽  
Power Level ◽  
Power Spectra ◽  
Normal Subjects ◽  
Acoustic Power ◽  
Preliminary Study ◽  
A New Technique ◽  
Second Formant ◽  
The One ◽  
Nasal Resonance

A new technique for evaluating hypernasality using an acoustic approach is presented. In a preliminary study using this technique, nasal resonance was assessed in 17 normal subjects and 16 subjects judged to be hypernasal. Analyses of the one-third-octave power spectra revealed an increase in power level between the first and second formant, and a reduction in the power level in second and third formant regions among utterances judged to be hypernasal. Factor analysis of the perceptual ratings revealed that the consensus perception of hypernasality accounted for 71% of the total variance. An additional 8% was accounted for by individual differences. Multiple regression analysis revealed a high correlation between the consensus perception of hypernasality and the variance in two acoustic-power levels, these being the power level between the first and second formant and the power level of the second and third formant regions.

scholarly journals Entropy rate defined by internal wave scattering in long-range propagation

2015 ◽  
Vol 138 (3) ◽  
pp. 1353-1364 ◽  
Author(s):  
Andrey K Morozov ◽  
John A. Colosi
Keyword(s):  
Internal Wave ◽  
Long Range ◽  
Wave Scattering ◽  
Entropy Rate

Acoustic normal mode fluctuation statistics in the 1995 SWARM internal wave scattering experiment

2000 ◽  
Vol 107 (1) ◽  
pp. 201-220 ◽  
Author(s):  
Robert H. Headrick ◽  
James F. Lynch ◽  
John N. Kemp ◽  
Arthur E. Newhall ◽  
Keith von der Heydt ◽  
...  
Keyword(s):  
Internal Wave ◽  
Normal Mode ◽  
Wave Scattering ◽  
Scattering Experiment

Structure- and Fluid-Borne Acoustic Power Sources in 90 Degree Piping Elbows Excited by Turbulent Flow

2006 ◽  
Author(s):  
Stephen A. Hambric ◽  
David A. Boger ◽  
John B. Fahnline ◽  
Robert L. Campbell
Keyword(s):  
Fluid Flow ◽  
Structural Parameters ◽  
Power Spectra ◽  
Acoustic Power ◽  
Flow Speed ◽  
Piping System ◽  
Power Sources ◽  
Turbulent Fluid Flow ◽  
Turbulent Fluid ◽  
Wall Pressure Fluctuations

The structure-borne and fluid-borne vibro-acoustic power spectra induced by turbulent fluid flow over the walls of a continuous 90 degree piping elbow are computed. Although the actual power input by the wall pressure fluctuations to the piping is distributed throughout the elbow, equivalent total powers input to various structural wavetypes (bending, torsion, axial) and fluid (plane waves) at the inlet and discharge of the elbow are computed. The powers at the elbow ‘ports’ are suitable inputs to wave-based and statistically-based models of larger piping systems that include the elbow. Calculations for several flow and structural parameters, including pipe wall thickness, flow speed, and flow Reynolds number are shown. The power spectra are scaled on flow and structural-acoustic parameters so that levels for conditions other than those considered in the paper may be estimated, subject to geometric similarity constraints (elbow radius/pipe diameter). The approach for computing the powers, which links Computational Fluid Dynamics, Finite Element and Boundary Element modeling, and efficient random analysis techniques, is general, and may be applied to other piping system components excited by turbulent fluid flow, such as U-bends and T-sections.

Cauchy internal wave scattering by density field inhomogeneities

1987 ◽  
Vol 28 (2) ◽  
pp. 246-249
Author(s):  
S. P. Budanov ◽  
A. S. Tibilov ◽  
V. A. Yakovlev
Keyword(s):  
Internal Wave ◽  
Wave Scattering ◽  
Density Field

Production of directionally limited acoustic power spectra

1991 ◽  
Vol 90 (2) ◽  
pp. 1213-1213
Author(s):  
Michael J. Greenwood ◽  
David P. J. Coughtrie
Keyword(s):  
Power Spectra ◽  
Acoustic Power
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