Generation of Aerodynamic Sound by Dilatation and Momentum Fluctuations

1961 ◽  
Vol 33 (11) ◽  
pp. 1684-1684
Author(s):  
Alan Powell
Keyword(s):  
Aerodynamic Sound

Staggered-mesh computation for aerodynamic sound

1998 ◽  
Author(s):  
G. Djambazov ◽  
C.-H. Lai ◽  
K. Pericleous
Keyword(s):  
Aerodynamic Sound

Study on acoustic and flow-induced noise characteristics of L-shaped duct with a shallow cavity

2020 ◽  
Vol 68 (3) ◽  
pp. 209-225
Author(s):  
Masaaki Mori ◽  
Kunihiko Ishihara
Keyword(s):  
Air Conditioning ◽  
Sound Field ◽  
Frequency Range ◽  
Acoustic Characteristics ◽  
Inflow Velocity ◽  
Aerodynamic Sound ◽  
Noise Characteristics ◽  
Flow Induced Noise ◽  
Shallow Cavity ◽  
Conditioning Equipment

An aerodynamic sound generated by a flow inside a duct is one of the noise pro- blems. Flows in ducts with uneven surfaces such as grooves or cavities can be seen in various industrial devices and industrial products such as air-conditioning equipment in various plants or piping products. In this article, we have performed experiments and simulations to clarify acoustic and flow-induced sound characteris- tics of L-shaped duct with a shallow cavity installed. The experiments and simula- tions were performed under several inflow velocity conditions. The results show that the characteristics of the flow-induced sound in the duct are strongly affected by the acoustic characteristics of the duct interior sound field and the location of the shallow cavity. Especially, it was found that the acoustic characteristics were af- fected by the location of the shallow cavity in the frequency range between 1000 Hz and 1700 Hz.

Mitigation of aerodynamic sound for a laminar flow past a square cylinder using a pair of cowl plates

2020 ◽  
Vol 32 (7) ◽  
pp. 076108 ◽  
Author(s):  
Bikash Mahato ◽  
Naveen Ganta ◽  
Yogesh G. Bhumkar
Keyword(s):  
Laminar Flow ◽  
Square Cylinder ◽  
Aerodynamic Sound ◽  
Flow Past

Trailing edge flows and aerodynamic sound

1988 ◽  
Author(s):  
JONATHAN GERSHFELD ◽  
WILLIAM BLAKE ◽  
CHARLES KNISELY
Keyword(s):  
Trailing Edge ◽  
Aerodynamic Sound

Shallow water wave generation by unsteady flow

1968 ◽  
Vol 31 (4) ◽  
pp. 779-788 ◽  
Author(s):  
J. E. Ffowcs Williams ◽  
D. L. Hawkings
Keyword(s):  
Shallow Water ◽  
Water Waves ◽  
Water Wave ◽  
Small Amplitude ◽  
Point Of View ◽  
Sound Waves ◽  
Aerodynamic Sound ◽  
Shallow Layer ◽  
Sound Theory ◽  
Water Simulation

Small amplitude waves on a shallow layer of water are studied from the point of view used in aerodynamic sound theory. It is shown that many aspects of the generation and propagation of water waves are similar to those of sound waves in air. Certain differences are also discussed. It is concluded that shallow water simulation can be employed in the study of some aspects of aerodynamically generated sound.

Aerodynamic sound generation of flapping wing

2008 ◽  
Vol 124 (1) ◽  
pp. 72-81 ◽  
Author(s):  
Youngmin Bae ◽  
Young J. Moon
Keyword(s):  
Flapping Wing ◽  
Sound Generation ◽  
Aerodynamic Sound

Numerical Study on Air-Reed Instruments With LES

2011 ◽  
Author(s):  
Kin’ya Takahashi ◽  
Masataka Miyamoto ◽  
Yasunori Ito ◽  
Toshiya Takami ◽  
Taizo Kobayashi ◽  
...  
Keyword(s):  
Numerical Study ◽  
Sound Field ◽  
Acoustic Analogy ◽  
Empirical Theory ◽  
Sound Sources ◽  
Aerodynamic Sound ◽  
Eddy Simulation ◽  
Large Eddy ◽  
Semi Empirical ◽  
2D And 3D

The acoustic mechanisms of 2D and 3D edge tones and a 2D small air-reed instrument have been studied numerically with compressible Large Eddy Simulation (LES). Sound frequencies of the 2D and 3D edge tones obtained numerically change with the jet velocity well following Brown’s semi-empirical equation, while that of the 2D air-reed instrument behaves in a different manner and obeys the semi-empirical theory, so called Cremer-Ising-Coltman theory. We have also calculated aerodynamic sound sources for the 2D edge tone and the 2D air-reed instrument relying on Ligthhill’s acoustic analogy and have discussed similarities and differences between them. The sound source of the air-reed instrument is more localized around the open mouth compared with that of the edge tone due to the effect of the strong sound field excited in the resonator.

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