Broadband Sound Absorption of Subwavelength Porous Meta-Liner

This work proposes a subwavelength porous meta-liner with broadband sound absorption from 900 to 1,200 Hz. The consists of four subunits, which are made up material and hollow coiling slit embedded in it. Each subunit is designed by adjusting the length its achieve resonance target frequency examined finite element method (FEM). These subunits arranged an axial direction uniformly radial periodically propose duct. Then, noise reduction propeller system duct measured microphone array. result shows that can reduce level ducted between 3.6 5.5 dB design range, also effectively reduces range. Therefore, good application prospect propeller.