Multimodal Far-Field Acoustic Radiation Pattern Using Mode Cutoff Ratio

AIAA Journal ◽  
1978 ◽  
Vol 16 (9) ◽  
pp. 906-911 ◽  
Author(s):  
Edward J. Rice
Keyword(s):  
Radiation Pattern ◽  
Acoustic Radiation ◽  
Far Field ◽  
Mode Cutoff

scholarly journals Study on Acoustic Radiation Calculation and Far Field Criterion of Oil pan

2021 ◽  
Vol 1043 (4) ◽  
pp. 042062
Author(s):  
Yue-zhen Huang ◽  
Bo Zhang ◽  
Ke-lun Zhao ◽  
Xue-bao Xia
Keyword(s):  
Acoustic Radiation ◽  
Far Field ◽  
Field Criterion

Relationships Between Acoustic Radiation Modes, Complex Acoustic Power, and Radiation Efficiency

1997 ◽  
Author(s):  
Pei-Tai Chen
Keyword(s):  
Acoustic Radiation ◽  
Acoustic Power ◽  
Radiation Efficiency ◽  
Acoustic Energy ◽  
Normal Velocity ◽  
Far Field ◽  
Surface Complex ◽  
Surface Integral ◽  
Complex Power ◽  
Mass Spring

Abstract The paper explores the physical meaning underlying the surface complex acoustic power of a vibrating body, and its relationship to radiation efficiency under mono-frequency oscillations. The vibrating can be the entire wetted surface, or only a part of the surface with the remaining surface being held rigid. The surface complex acoustic power can be computed by the surface integral of pressure multiplying the complex conjugate of normal velocity. Based on the Gaussian Divergence theorem, it is shown that the real part of the complex power is the power radiated into a far field, while that the imaginary part pertains to the volume integral of the difference between the acoustic kinetic energy density with the potential energy density over the volume between the vibrating surface and the far field. The dynamical behavior of the acoustic field can be viewed as an infinite degree of freedom mass/spring/dashpot system, where the mass and spring are the inertia effects and acoustic compression effects of the acoustic particles and the dashpot is due to the plane wave relationship of the pressure waves at the far field that the acoustic energy propagates away from the acoustic field. By the model of the mass /spring/dashpot system, the phase angle of the complex acoustic power is identified as an indication of the ability of the vibrating surface to radiate acoustic power. The phase angle of the complex power depends on the distribution of the surface normal velocity. In order to study the normal velocity profile in relation to the ability to radiate acoustic energy, the previously established radiation mode (Chen and Ginsberg, 1995) is introduced and extended to situations in which a part of the surface is held rigid. An orthogonal condition for the velocity radiation modes is also established such that arbitrary velocity profiles can be decomposed into radiation modes. The acoustic modal radiation efficiency, defined as the radiated modal acoustic power divided by the surface integral of mean square normal velocity, is investigated in terms of the acoustic eigenvalue of that mode. Several different geometries of vibrating bodies are used to demonstrate the correlation of radiation efficiencies to eigenvalues of radiation modes, which include a rectangular baffled vibrating membrane, a box with only one of the six surfaces vibrating, a slender spheroidal body, and a spherical body. This correlation of acoustic radiation characteristics for different geometries is also demonstrated for a spheroidal body vibrating at some areas with other areas being held rigid.

On near- and far-field acoustic radiation characteristics of ships in finite-depth water environment

2021 ◽  
Vol 172 ◽  
pp. 107644
Author(s):  
Ming-Song Zou ◽  
Shu-Xiao Liu ◽  
Yi-Ni Yang
Keyword(s):  
Acoustic Radiation ◽  
Water Environment ◽  
Finite Depth ◽  
Far Field ◽  
Radiation Characteristics ◽  
Depth Water

scholarly journals Capturing the Acoustic Radiation Pattern of Strombolian Eruptions using Infrasound Sensors Aboard a Tethered Aerostat, Yasur Volcano, Vanuatu

2017 ◽  
Vol 44 (19) ◽  
pp. 9672-9680 ◽  
Author(s):  
Arthur D. Jolly ◽  
Robin S. Matoza ◽  
David Fee ◽  
Ben M. Kennedy ◽  
Alexandra M. Iezzi ◽  
...  
Keyword(s):  
Radiation Pattern ◽  
Acoustic Radiation ◽  
Strombolian Eruptions

Comment on ‘Correction of errors in aerial far-field radiation-pattern determinations’

1971 ◽  
Vol 7 (24) ◽  
pp. 706
Author(s):  
D.M. Kerns
Keyword(s):  
Radiation Pattern ◽  
Far Field ◽  
Field Radiation
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