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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.

2

Acoustic Pressure Radiated by a Circular Membrane Into the Quarter-Space

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

Archives of Acoustics

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2011

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Vol. 36, No. 1

121-139

EN

The Neumann boundary value problem for the Helmholtz equation within the quarter-space has been considered in this paper. The Green function has been used to find the acoustic pressure amplitude as the approximation valid within the Fraunhoffer’s zone for some time-harmonic steady state processes. The low fluid loading has been assumed and the acoustic attenuation has been neglected. It has also been assumed that the vibration velocity of the acoustic particles is small as compared with the sound velocity in the gaseous medium.

3

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.