0469397 - ÚFP 2017 RIV AR eng C - Konferenční příspěvek (zahraniční konf.)
Steiger, Kateřina - Mokrý, P. - Václavík, J. - Psota, Pavel - Doleček, Roman - Vápenka, David - Nečásek, J. - Koldovský, Z.
Adaptive acoustic metasurfaces for the active sound field control.
PROCEEDINGS of the 22nd International Congress on Acoustics. Buenos Aires: Asociación de Acústicos Argentinos, 2016, č. článku ICA2016-597. ICA. ISBN 978-987-24713-6-1. ISSN 2415-1599.
[International Congress on Acoustics (ICA2016) /22./. Buenos Aires (AR), 05.09.2016-09.09.2016]
Grant CEP: GA MŠMT(CZ) LO1206; GA ČR(CZ) GA16-11965S
Institucionální podpora: RVO:61389021
Klíčová slova: Adaptive acoustic metasurfaces * Active sound field control
Kód oboru RIV: JI - Kompozitní materiály
http://www.ica2016.org.ar/ica2016proceedings/ica2016/ICA2016-0597.pdf

Active acoustic metasurfaces (AAMSs) have been recently recognized as very efficient soundshielding structures, which can have large lateral dimensions perpendicular to the direction ofthe sound wave propagation but very short lateral dimension along the direction of the soundwavevector. The sound shielding principle of AAMSs is based on control of the specific acoustic impedance (SAI). This is achieved by means of an active tuning of elastic properties of piezoelectric transducers, which, therefore, represent the core element of the AAMSs. Using this approach, it is possible to actively control the acoustic coefficients of transmission and reflection of AAMSs. An important point, which has been recently discovered, is the fact that the great suppression of the transmission coefficient can be achieved in the regime, when the SAI of the AAMS is negative. The function of the AAMS in varying operational conditions or in a wide frequency range, however, put delicate stability conditions on the negative values of SAI. In order to keep the AAMS in the stable operation, a concept of adaptive acoustic metasurfaces (AdAMSs) is introduced in this paper. Methods for the real-time estimation and the active control of the SAI values of the AdAMSs are presented. It is shown that the accurate control of the distribution of the SAI on the surface of the AdAMS enables to control the transmitted sound field not only in the magnitude but also in the direction of the transmitted sound wave.
Trvalý link: http://hdl.handle.net/11104/0267180