Development of the numerical method for calculating sound radiation from a rotating dipole source in an opened thin duct

2006 ◽  
Vol 295 (3-5) ◽  
pp. 739-752 ◽  
Author(s):  
Han-Lim Choi ◽  
Duck Joo Lee
Keyword(s):  
Numerical Method ◽  
Sound Radiation ◽  
Dipole Source

A combined experimental and numerical method for computing sound radiation from underwater vibrating structures

1997 ◽  
Vol 102 (5) ◽  
pp. 3067-3067
Author(s):  
John B. Fahnline ◽  
Matthew J. Erickson ◽  
Dean E. Capone ◽  
Stephen A. Hambric ◽  
Courtney B. Burroughs
Keyword(s):  
Numerical Method ◽  
Sound Radiation ◽  
Vibrating Structures

A numerical method for computation of sound radiation from an unflanged duct

2004 ◽  
Vol 270 (3) ◽  
pp. 573-586 ◽  
Author(s):  
X.X. Chen ◽  
X. Zhang ◽  
C.L. Morfey ◽  
P.A. Nelson
Keyword(s):  
Numerical Method ◽  
Sound Radiation

Computational Estimation of Fan Casing Noise at Blade Passing Frequency Component Noise

2012 ◽  
Vol 184-185 ◽  
pp. 95-100
Author(s):  
Jian Cheng Cai ◽  
Yong Hai Zhang ◽  
Shuang Li Long
Keyword(s):  
Pressure Fluctuation ◽  
Pressure Fluctuations ◽  
Sound Radiation ◽  
Internal Flow ◽  
Neumann Boundary ◽  
Frequency Component ◽  
Dipole Source ◽  
Centrifugal Fan ◽  
Element Analysis ◽  
Blade Passing Frequency

This paper studies both vibroacoustics and aeroacoustics of a centrifugal fan casing; the aim of this study is to explore a methodology to make quantitative predictions of fan casing noise. The spectra of the fan noise and casing vibration were firstly presented; discrete components related to the rotational frequency protrude in the spectra, especially the blade passing frequency (BPF). Computational fluid dynamics (CFD) technique was used to obtain the three-dimensional unsteady turbulent internal flow. Attention was paid to the pressure fluctuations on the volute wall; the shapes of pressure fluctuation were nearly sinusoidal in nature, with the BPF as the primary frequency. On the vibroacoustic side, Fast Fourier Transform (FFT) was applied to the time series of pressure fluctuations to extract the BPF component. A finite element analysis (FEA) model of the casing structure was constructed, and was validated by experimental modal analysis. The harmonic dynamic response of the casing structure was calculated with the BPF pressure fluctuation component as the excitation. The vibration results were then taken as the velocity (Neumann) boundary condition for the noise radiation model which was built in boundary element method (BEM), and the sound radiation was calculated. On the aeroacoustic side, the BPF component of pressure fluctuations was modeled as acoustic dipole source, and sound radiation was also solved by BEM. Results show that the sound pressure level (SPL) of vibroacoustics is fairly small compared to the aeroacoustic counterpart. This study shows that CFD, FEA together with BEM can be used to numerically predict BPF casing noise of turbomachinery successfully.

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