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Multi-Layered Porous Helmholtz Resonators for Low-Frequency and Broadband Sound Absorption
Xuewei Liu1,2, Tianyu Gu1,2, Ling Li1,2
1School of Mechanical and Electrical Engineering, Xi'an University of Architecture and Technology, Xi'an 710055, China.
Materials (Basel, Switzerland)
|February 13, 2026
Summary
This study introduces a novel multi-layered porous Helmholtz resonator absorber for superior sound absorption. The innovative design achieves ultra-broadband sound absorption with larger, easier-to-fabricate orifices, outperforming traditional micro-perforated panels.
Area of Science:
- Acoustics
- Materials Science
- Mechanical Engineering
Background:
- Classical multi-layered micro-perforated panels (MPPs) use sub-millimeter orifices for sound dissipation.
- Porous materials offer potential for enhanced sound energy dissipation.
Purpose of the Study:
- To propose and validate a novel multi-layered porous Helmholtz resonator absorber.
- To investigate its sound absorption performance and compare it with conventional MPPs.
Main Methods:
- Theoretical modeling using double porosity theory and bottom-to-top impedance translation.
- Experimental validation with a double-layered prototype.
- Numerical simulations of sound pressure, particle velocity, and energy flow.
Main Results:
- A double-layered prototype achieved near-perfect absorption peaks at 262 Hz and 774 Hz with 11 cm thickness.
- Broadband absorption (coefficient > 0.7) was achieved from 202 Hz to 1076 Hz.
- An optimized triple-layer absorber demonstrated ultra-broadband absorption (coefficient > 0.95) from 280 Hz to 1349 Hz with 16.5 mm thickness.
Conclusions:
- The multi-layered porous Helmholtz resonator absorber effectively enhances sound absorption through Helmholtz resonances within porous layers.
- The design offers significant advantages over traditional MPPs, including larger, easier-to-fabricate orifices and improved resistance to blockage.
- This offers a promising alternative for low-frequency and broadband sound absorption applications.
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