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Sound Radiation from a Surface Source Located at the Bottom of the Wedge Region

Szemela K.

Archives of Acoustics

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2015

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Vol. 40, No. 2

223--234

EN

Applying rigorous analytical methods, formulas describing the sound radiation have been obtained for the wedge region bounded by two transverse baffles with a common edge and bottom. It has been assumed that the surface sound source is located at the bottom. The presented formulas can be used to calculate the sound pressure and power inside the wedge region. They are valid for any value of the wedge angle and represent a generalization of the formulas describing the sound radiation inside the two and three-wall corner region. Moreover, the presented formulas can be easily adapted for any case when more than one sound source is located at the bottom. To demonstrate their practical application, the distribution of the sound pressure modulus and the sound power have been analyzed in the case of a rectangular piston located at the wedge’s bottom. The influence of the transverse baffle on the sound power has been investigated. Based on the obtained formulas, the behaviour of acoustic fields inside a wedge can be predicted.

2

The Acoustic Impedance of a Vibrating Annular Piston Located on a Flat Rigid Baffle Around a Semi-Infinite Circular Rigid Cylinder

Rdzanek W. P., Rdzanek W. J., Pieczonka D.

Archives of Acoustics

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2012

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Vol. 37, No. 4

411-422

EN

The axisymmetric problem of acoustic impedance of a vibrating annular piston embedded into a flat rigid baffle concentrically around a semi-infinite rigid cylindrical circular baffle has been undertaken in this study. The Helmholtz equation has been solved. The Green’s function valid for the zone considered has been used for this purpose. The influence of the semi-infinite cylindrical baffle on the piston’s acoustic impedance has been investigated. The acoustic impedance has been presented in both forms: integral and asymptotic, both valid for the steady harmonic vibrations. Additionally, the acoustic impedances of the piston with and without the cylindrical baffle have been compared to one another. In the case without the cylindrical baffle some earlier results have been used.

3

Acoustic Power Radiated by a System of Two Vibrating Circular Membranes Located at the Boundary of Three-Wall Corner Spatial Region

Szemela K., Rdzanek W. P., Rdzanek W. J.

Archives of Acoustics

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2012

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Vol. 37, No. 4

463-473

EN

Two vibrating circular membranes radiate acoustic waves into the region bounded by three infinite baffles arranged perpendicularly to one another. The Neumann boundary value problem has been inves- tigated in the case when both sources are embedded in the same baffle. The analyzed processes are time harmonic. The membranes vibrate asymmetrically. External excitations of different surface distributions and different phases have been applied to the sound sources’ surfaces. The influence of the radiated acoustic waves on the membranes’ vibrations has been included. The acoustic power of the sound sources system has been calculated by using a complete eigenfunctions system.

4

Acoustic power radiated into the quarter-space by a circular membrane with an asymmetric excitation

Rdzanek W. P., Rdzanek W. J., Szemela K.

Archives of Acoustics

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2009

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Vol. 34, No. 1

75-94

EN

A circular membrane excited asymmetricaly is vibrating and radiating acoustic waves into the quarter-space limited by two rigid baffles arranged perpendicularly to one another. These processes are time harmonic. The classical Neumann boundary value problem has been solved using the complete eigenfunctions system together with the corresponding coupling matrix and including the acoustic attenuation effect.

5

Sound pressure radiation of a circular piston located at a two- and three-wall corners

Rdzanek W. P., Szemela K., Pieczonka D.

Archives of Acoustics

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2007

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Vol. 32, No. 4

883--893

EN

This paper focuses on the far eld approximation of the steady state sound pressure radiated by a at circular piston into the region bounded by some at rigid bafes. The two Neumann boundary value problems have been considered for the regions of two- and three-wall corners, separately. The Green function in its Fourier representation has been used together with the Sommerfeld radiation condition which has given the sound pressure approximation in the form of some useful elementary formulations. The boundary value problems often appear in the situation when the sound source is located in the vicinity of the Earth and some vertical walls, e.g. the sound barriers, the building walls, etc.