SeMSA: a compact super absorber optimised for broadband, low-frequency noise attenuation

Area of Science:

• Acoustics
• Materials Science
• Mechanical Engineering

Background:

• Attenuating low-frequency broadband noise in compact devices presents significant engineering challenges.
• Existing sound absorption technologies often struggle to achieve effective low-frequency performance without substantial bulk.
• Visco-thermal loss mechanisms offer potential for efficient sound absorption.

Purpose of the Study:

• To introduce a new sound absorber technology for effective low-frequency broadband noise attenuation.
• To demonstrate the capability of this technology in achieving deep sub-wavelength thicknesses.
• To compare the performance of the new design against existing sound absorption methods.

Main Methods:

• Development of the Segmented Membrane Sound Absorber (SeMSA) design.
• Integration of micro-perforated plates (MPP) with decorated membrane resonators (DMR).
• Utilizing visco-thermal loss mechanisms within the MPP.
• Validation through analytical, finite element, and experimental analyses.

Main Results:

• The SeMSA design demonstrates highly efficient low-frequency broadband sound absorption.
• The SeMSA achieves significant noise reduction at deep sub-wavelength thicknesses.
• Comparative analysis shows the SeMSA outperforms existing absorbers in the 20-1200 Hz range for depths up to 120 mm.

Conclusions:

• The SeMSA represents a breakthrough in compact, lightweight low-frequency sound absorption.
• The combination of MPP and DMR technologies offers a powerful solution for noise control.
• This technology holds promise for applications requiring effective sound attenuation in space-constrained environments.