Acoustic gradient surfaces and gradient-index surfaces: Principles and applications on noise control

Autor:	Dongxing Mao, Xu Wang, Jiang Zaixiu, Xiaonan Wang, Yu Wuzhou
Rok vydání:	2019
Předmět:	Wavelength Materials science Acoustics and Ultrasonics Acoustics visual_art Electromagnetic shielding Microscopy Noise control visual_art.visual_art_medium Surface impedance Environmental noise Engraving Oblique reflection
Zdroj:	Applied Acoustics. 143:151-156
ISSN:	0003-682X
DOI:	10.1016/j.apacoust.2018.08.021
Popis:	Gradient surfaces (oblique reflection surfaces) and gradient-index surfaces (surfaces engraved by a series of 1/4 wavelength tubes with linearly growing length) are two solutions on manipulating the reflected sound field. For a high-rise building built close to a traffic road, implementing these two solutions in balcony ceiling design on upper floors both provide remarkable noise insertion losses. This paper presents a systematical comparison between these two surfaces, theoretically and numerically. Our results reveal their distinct underlying working mechanisms: one works by its profile (a macroscopy effect), while the other works by the multiple interferences from its distribute surface impedance (a microscopy effect). The advantage of the gradient-index surface on shielding the balcony region is further demonstrated. This paper may pave the way for the application of the gradient-index surfaces in environmental noise control.
Databáze:	OpenAIRE
Externí odkaz:	https://explore.openaire.eu/search/publication?articleId=doi_________::22456a70ddd076c0a30587b311e0860f https://doi.org/10.1016/j.apacoust.2018.08.021 Zobrazit plný text záznamu Full Text from ScienceDirect