Broadband noise insulation of windows using coiled-up silencers consisting of coupled tubes

Abstract

It has been demonstrated that a staggered window achieves better noise reduction performance than a traditional single glazing one at middle to high frequencies while maintaining a degree of natural ventilation. There is, however, little improvement in the low frequency range. In contrast, this work proposes to apply coiled-up silencers consisting of coupled tubes on the side walls of staggered windows to obtain noise attenuation in a broad band, especially in the low frequency range. Each element in the silencer consists of two coupled tubes with different cross sections so that noise at more frequencies can be attenuated than that with a uniform cross section. The simulation results show that 8.8 dB overall insertion loss can be obtained between 100 and 500 Hz after applying a combination of silencers designed at 7 different frequencies, and the insertion loss of the staggered window is increased from 6.7 to 15.6 dBA between 100 and 2000 Hz for normal incident traffic noise with the proposed silencers installed. The design is validated by the experiments with a 1:4 scale down model.

Acoustic Metamaterials for Noise Reduction: A Review

“…For noise reduction applications requiring ventilation, acoustic metamaterials provide unconventional solutions. In fact, the acoustic facade systems originated early and were continuously developed for decades, from the earliest double-skin facade [138,139] to the plenum window [140][141][142][143][144] with a noise-reduction function. As a classical acoustic structure, Helmholtz resonators have great application potential in ventilation and sound-insulation metamaterials, enabled by the neck in its structure.…”

Remote work: Aircraft noise implications, prediction, and management in the built environment

“…Instead of sonic crystal, plenum windows can also be incorporated with labyrinthine array to introduce additional design parameters for performance tuning. Although several concepts were studied [168] , [169] , notable low-frequency performance was only recently reported in the work of Wang et al [159] . Wang et al [159] proposed a concept combining single-glazed window (bottom portion) and plenum window (top portion).…”

“…Although several concepts were studied [168] , [169] , notable low-frequency performance was only recently reported in the work of Wang et al [159] . Wang et al [159] proposed a concept combining single-glazed window (bottom portion) and plenum window (top portion). The plenum window was incorporated with a labyrinthine array consisting of 14 unit cells with differing dimensions.…”