Sound radiation from ducts: Theory and experiment

Hamdi, M. A.; Ville, Jean‐Michel

doi:10.1016/0022-460x(86)90234-8

Cited by 17 publications

(10 citation statements)

References 6 publications

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“…The BEM models were computed by using the 3-D RAYON code, based on a variational formulation of the integral form (38) [24]. The components of the full square matrix are double integrals over the surface , the second member is a simple integral over .…”

Section: Boundary Element Model Denitionmentioning

confidence: 99%

Radiation Impedance of Tubes With Different Flanges: Numerical and Experimental Investigations

Dalmont

Nederveen²,

Joly³

2001

Journal of Sound and Vibration

125

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Section: Boundary Element Model Denitionmentioning

confidence: 99%

Radiation Impedance of Tubes With Different Flanges: Numerical and Experimental Investigations

Dalmont

Nederveen²,

Joly³

2001

Journal of Sound and Vibration

125

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“…The boundary element method (BEM) has also been applied by several authors and in principle this method is capable of examining ducts of arbitrary crosssection, although to date only radiation from ducts with a circular cross-section has been examined. 5,20,21 For example, Dalmont et al 5 examined unflanged circular ducts, where they found it necessary to assign a finite length duct in place of the (nominally) infinite duct when modeling the duct exterior and so assume that the effect of this on the computed end correction is negligible. Dalmont et al do, however, note that their BEM approach gives inaccurate results for values of Helmholtz number less than 0.18 (based on duct radius); this is probably due to the BEM finding it difficult to resolve low values of acoustic pressure in the exterior sound field.…”

Section: Introductionmentioning

confidence: 98%

A hybrid finite element approach to modeling sound radiation from circular and rectangular ducts

Duan

Kirby

2012

The Journal of the Acoustical Society of America

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A numerical model based on a hybrid finite element method is developed that seeks to join sound pressure fields in interior and exterior regions. The hybrid method is applied to the analysis of sound radiation from open pipes, or ducts, and uses mode matching to couple a finite element discretization of the region surrounding the open end of the duct to wave based modal expansions for adjoining interior and exterior regions. The hybrid method facilitates the analysis of ducts of arbitrary but uniform cross section as well the study of conical flanges and here a modal expansion based on spherical harmonics is applied. Predictions are benchmarked against analytic solutions for the limiting cases of flanged and unflanged circular ducts and excellent agreement between the two methods is observed. Predictions are also presented for flanged and unflanged rectangular ducts, and because the hybrid method retains the sparse banded and symmetric matrices of the traditional finite element method, it is shown that predictions can be obtained within an acceptable time frame even for a three dimensional problem.

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“…In acoustics, the BEM requires the acoustic variables within the acoustic domain to be expressed as a surface integral over the boundary of the domain. There are two different formulations for the BEM: (a) the direct [9,15] and (b) indirect methods [11,12]. The difference between them is a result of the choice of primary variables [16].…”

Section: Modeling Sound Fieldsmentioning

confidence: 99%

“…The two most commonly used numerical methods for solving acoustical problems are finite element methods [6][7][8] (FEM) and the boundary element [9][10][11][12][13] (BEM). The FEM solves the response in the acoustic domain itself by computing the mass and stiffness of the acoustic domain.…”

Section: Modeling Sound Fieldsmentioning

confidence: 99%

Investigating the Action of Complex Highway Noise Barriers by Means of Sound Field Visualization

Oldham

Egan

2007

Computer Graphics, Imaging and Visualisation (CGIV 2007)

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The performance of a simple noise barrier is determined by its height relative to the heights of the noise source and receivers. There have been many attempts to overcome this limitation by modifications to the barrier top edge. These generally take the form of an absorbent top or the introduction of additional diffracting edges. However, relatively minor variations in geometry have sometimes been found to result in drastic changes to barrier performance. In this paper the Boundary Element Method is employed to calculate the sound field in the vicinity of complex barrier tops and sound field visualization techniques are used with these data to investigate how the sound field varies with frequency and dimensional changes. It is shown that for some top edge configurations local resonance effects have a significant effect on the attenuation afforded by the barrier.

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Sound radiation from ducts: Theory and experiment

Cited by 17 publications

References 6 publications

Radiation Impedance of Tubes With Different Flanges: Numerical and Experimental Investigations

Radiation Impedance of Tubes With Different Flanges: Numerical and Experimental Investigations

A hybrid finite element approach to modeling sound radiation from circular and rectangular ducts

Investigating the Action of Complex Highway Noise Barriers by Means of Sound Field Visualization

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