Diffusive surface design using Sierpinski triangle fractal structures

Conference paper (2022)

Authors

Lingge Tan Harbin Institute of Technology
Jieun Yang Eindhoven University of Technology
Jian Kang University College London
Hongpeng Xu Harbin Institute of Technology
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Fractal Acoustic diffuser Sierpinski triangle
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Published Date

2022-10

Language

English

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Abstract

Diffusive surfaces can be optimally designed for both acoustic and aesthetic purposes. Adapting to the parametric demands of interface design, fractals are widely applied as a fusion of mathematical calculation and artistic design. The Sierpinski triangle is a self-similar structure with a more impressive appearance than conventional acoustic diffusers. However, the acoustic performance of Sierpinski fractal patterns has not been considered. This paper proposes a design of an acoustic diffuser based on the construction rules of the Sierpinski triangle to broaden the effective frequency range. The diffuser is made of triangular blocks of different sizes attached to a plane surface. A series of case studies are examined through numerical simulations based on the boundary element method (BEM) to investigate the effects of the number of iterations, the randomness of block arrangements, and the inclination of block tops. The diffusion performance of a conventional quadratic residue diffuser (QRD) is compared to confirm the advantage of the designed diffuser for broadening the effective frequency range. Furthermore, a workflow of the design and evaluation processes is presented to fabricate samples that could be used to tune the design parameters according to their in-field application demands.