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A 1-D Non-Local Metasurface-Based Broadband Acoustic Diffuser
Zhuoma Wang1, Ruoyan Li2,3, Wenjing Ye2,*, Yijun Liu3
1 Division of Emerging Interdisciplinary Areas, The Hong Kong University of Science and Technology, Clear Water Bay,
Kowloon, Hong Kong, China
2 Department of Mechanical and Aerospace Engineering, The Hong Kong University of Science and Technology, Clear
Water Bay, Kowloon, Hong Kong, China
3 Department of Mechanics and Aerospace Engineering, Southern University of Science and Technology, 1088 Xueyuan
Avenue, Shenzhen, 518055, China
* Corresponding Author: Wenjing Ye. Email:
The International Conference on Computational & Experimental Engineering and Sciences 2023, 27(4), 1-2. https://doi.org/10.32604/icces.2023.09236
Abstract
An acoustic diffuser refers to a device that spreads sound energy uniformly in all directions. Such a device
plays a very important role in architectural acoustics, i.e., concert halls and auditoriums. Many designs such
as the wellknown Schroeder diffusers [1] have been proposed and developed throughout the past several
decades. However, most of these conventional designs achieve uniform sound diffusion by using different
air trenches to create a phase shift profile following a specific sequence such as maximum length sequence
or quadratic residue sequence derived from the number theory [1,2]. As such, these diffusers have
considerable thicknesses, which makes them difficult to be applied in certain practical settings. Recently,
metasurface-based diffusers have been proposed. These local resonator-based diffusers can significantly
reduce the thickness, resulting in ultrathin diffusers that potentially have high commercial values [3,4].
However, resonators naturally have narrow bands. Hence, designing high-performance broadband
resonator-based diffusers is challenging. In this talk, we will present a general design methodology based
on genetic algorithm (GA) and topology optimization (TO) for the design of broadband metasurface-based
acoustic diffusers. The diffusion performance is set explicitly as the design objective and a nonlocal design
is carried out with the consideration of the interaction between different parts of the diffuser. Hence, optimal
designs are no longer limited to designs based on specific phase shift profiles and high-performance can be
achieved. Several designs targeting at different frequency ranges will be presented. Numerical results show
that the proposed designs have comparable or even better performance compared to Schroeder diffusers
over a broad frequency range and wide incident angles, but with much reduced thicknesses.
Keywords
Cite This Article
Wang, Z., Li, R., Ye, W., Liu, Y. (2023). A 1-D Non-Local Metasurface-Based Broadband Acoustic Diffuser.
The International Conference on Computational & Experimental Engineering and Sciences, 27(4), 1–2. https://doi.org/10.32604/icces.2023.09236