Full-text resources of PSJD and other databases are now available in the new Library of Science.
Visit https://bibliotekanauki.pl
Preferences help
Polish version English version Language
enabled [disable] Abstract
Number of results

Results found: 4

Number of results on page
first rewind previous Page / 1 next fast forward last

Search results

Search:
in the keywords:  43.40.Rj
help Sort By:

help Limit search:
first rewind previous Page / 1 next fast forward last
1
Content available remote

The Influence of Sound Source Directivity on Acoustics Parameters Distribution in Kraków Opera House

100%
Gołaś A., Suder-Dębska K., Filipek R.
|
EN
Determining of Kraków Opera House's basic acoustics parameters by using numerical simulations is presented in the paper. Parameters have been obtained by using numerical simulation methods. Sound sources have been created by means of FEA, however acoustic field distributions have been analysed by geometrical methods. Apart from the room parameters definition, it is necessary to determine sound source parameters like acoustic power level and directivity pattern. In the simplest case, the sound source can be assumed as omni-directional point source. However it does not reflect most real-live sources precisely. When the literature and databases do not contain any information about the sound source directivity pattern, it can be obtained numerically using FEA. First, the sound source model is created, and then results from its spherical boundary are used to define the source in a program based on geometrical methods. Here have been analysed several distributions of acoustic parameters like: Direct Energy, Sound Pressure Level (SPL), Clarity index (C80) etc. The results indicate that influence of sound source directivity on acoustics parameters changes is essential.
2
Content available remote

Acoustic Nearfield and Farfield for Vibrating Piston in Geometrical and Intensity Formulations

100%
Kozień M.
Acta Physica Polonica A
|
2012
|
vol. 121
|
issue 1A
A-132-A-135
EN
In classic acoustics there are two areas identified around acoustic sources - nearfield and farfield. The nearfield is connected with the Fresnel solution and farfield - the Fraunhofer one. For each regions there are different theoretical formulae for determination of distribution of the chosen acoustic parameter. Unfortunately there is no sharply outlined border between regions. Therefore one of the important problem, is to define approximately conditions for state the border between them. The two attempts for identification are discussed, i.e. geometrical one and intensity ones. The results are shown on the vibrating circular rigid piston case.
3
Content available remote

Comparison of Passive and Active Methods for Minimization of Sound Radiation by Vibrating Clamped Plate

88%
Kozupa M., Wiciak J.
Acta Physica Polonica A
|
2011
|
vol. 119
|
issue 6A
1013-1017
EN
The paper is an analytical and experimental study of a smart structure consisting of steel plate with bonded piezoelectric transducers and porous elastomer layer. Active control of sound radiation from a plate clamped at the edge square is examined. Simulations and numerical computation of the experiment are performed in Ansys environment. Calculations of plate vibration and sound radiation under stepped harmonic force are performed. The experimental setup consists of two rooms with the test opening in between. A variety of test cases were studied for three different configurations: steel plate + piezoelectric transducer, steel plate + elastomer layer, steel plate + piezoelectric transducer + elastomer layer. The aim of the paper is to illustrate the possibilities of using piezoelectric materials as an active control with elastomer layers as passive methods in one structure to improve the transmission loss.
4
Content available remote

Synthesis of the Impulse Response of the Transmission Path in a Selected Area of the Sound Field

75%
Czajka I., Suder-Dębska K., Gołaś A.
Acta Physica Polonica A
|
2013
|
vol. 123
|
issue 6
1072-1077
EN
Providing appropriate sound field parameters in the listening area is very important. It often determines the possibilities of being able to use a facility. Assuming that the sound system is a linear object, it can be described by the impulse response. Unfortunately, it is not possible to designate a single impulse response for such a facility because it is a continuous system. Thus each path between the transmitter and the receiver has its own impulse response. Therefore, the authors have made an attempt to synthesize the impulse response for transmitter-receiver paths with suitable parameters of the sound field in the neighbourhood of the receivers. A technical implementation of the presented synthesis will take place through introduction of additional sources. An experimental determination of the impulse response is relatively simple. The transient response can be numerically determined by using, for example, the finite element method or the boundary element method. Unfortunately, determining the impulse response through simulation of, e.g., planned objects, is much more difficult due to the high computational cost and the lack of precise data on the properties of the materials. For this reason, the authors used an energetic analogue of the impulse response, the echogram.
first rewind previous Page / 1 next fast forward last
JavaScript is turned off in your web browser. Turn it on to take full advantage of this site, then refresh the page.