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Metasurface Lossless-Regulation Mechanism of Dynamic Acoustic Mass for Low-Frequency Aerodynamic Noise Control
1School of Mechanical Engineering, Xi'an Jiaotong University, Xi'an 710049, China.
Materials (Basel, Switzerland)
|November 27, 2025
Summary
A novel embedded-neck Helmholtz resonator (ENHR) metasurface effectively controls low-frequency aerodynamic noise. This dynamic acoustic mass regulation achieves significant transmission loss even with fluid flow.
Area of Science:
- Acoustics
- Fluid Dynamics
- Materials Science
Background:
- Helmholtz resonators (HR) struggle with low-frequency noise control due to flow-induced frequency shifts and amplitude reduction.
- Existing methods often fail to maintain acoustic attenuation under increasing fluid flow conditions.
Purpose of the Study:
- To investigate the lossless regulation mechanism of dynamic acoustic mass in embedded-neck Helmholtz resonator (ENHR) metasurfaces.
- To develop an effective method for low-frequency aerodynamic noise control under incident fluid flow.
Main Methods:
- Finite element simulation and wind tunnel experiments were employed.
- A flow-acoustic coupling aerodynamic simulation model for a ducted silencer system was established.
- The physical mechanism of dynamic acoustic mass regulation was specifically studied.
Main Results:
- A sub-wavelength, broadband ENHR metasurface with ten parallel cells was designed.
- An average transmission loss (TL) of 18.7 dB was achieved in the 70-200 Hz range at a Mach number (Ma) of 0.05.
- The study revealed the lossless regulation mechanism of dynamic acoustic mass.
Conclusions:
- The dynamic acoustic mass regulation mechanism in ENHR metasurfaces offers a promising solution for low-frequency aerodynamic noise.
- This metasurface design demonstrates significant potential for practical applications in noise control engineering.
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