Metahouse: Noise‐Insulating Chamber Based on Periodic Structures

Abstract

Noise pollution remains a challenging problem requiring the development of novel systems for noise insulation. Extensive work in the field of acoustic metamaterials has led to various ventilated structures which, however, are usually demonstrated for rather narrow regions of the audible spectrum. In this work, the idea of metamaterial‐based systems is further extended, developing the concept of a metahouse chamber representing a ventilated structure for multiple band noise insulation. Broad stop‐bands originate from strong coupling between pairs of Helmholtz resonators constituting the structure. The averaged transmission −18.6 dB are demonstrated numerically and experimentally within the spectral range from 1500 to 16 500 Hz. The sparseness of the structure together with the possibility to use optically transparent materials suggest that the chamber may be also characterized by partial optical transparency depending on the mutual position of structural elements. The obtained results are promising for development of novel noise‐insulating structures advancing urban science.

Broadband noise mitigation using coupled Helmholtz resonators: a numerical study

“…To form a periodic structure the resonators are arranged in pairs as it allows to broaden bang-gaps due to the strong local coupling [41]. The studies of transmission properties are performed for the semi-infinite structures which in this work are understood as structures having finite thickness along the direction of the incident plane wave propagation and infinitely periodic along the other direction [Figure 1(b)].…”

“…Unless it is stated otherwise, the thickness of the semiinfinite structure is 3 pairs of the resonators since in Ref. [41] it was demonstrated that such thickness is enough to experimentally observe pronounced stop-bands corresponding to the band-gaps of an equivalent infinite system [Figure 1(b)]. It might be argued that a structure with 3 unit cells can not be called a truly periodic one and variation of parameters in the direction of wave propagation is not enough to claim it to be chirped.…”

“…In order to stick to a particular design, we consider periodic structure based on strongly coupled Helmholtz resonators demonstrated in Ref. [41]. Using the physics-based approach supported by genetic algorithm optimization we demonstrate that chirping of local coupling between the resonators may lead to the formation of broad stop-band in the transmission spectra, which was observed numerically and experimentally.…”

Frequency‐independent Sound Absorbing Metamaterials

“…[12][13][14][15][16][17][18][19][20][21][22][23][24][25] Recently, the application of metamaterials has been extended to reduce tire noise and a noise insulating chamber. [26,27] Among various metamaterial designs, space-coiling metamaterials have attracted significant attention for their ability to achieve low-frequency absorption with deep subwavelength thickness. [15,16,[22][23][24][25] The extraordinary absorption performance is attributed to various mechanisms, including local resonance, [14,15] negative and zero effective material properties, [20,21] critical coupling, [16] Fabry-Pérot, and quarterwavelength resonance.…”