An ultra-thin low-frequency broadband metasurface with near-zero suppression of aerodynamic acoustic pressure

Li, Min; Wu, Jiu Hui; Wu, Bobo; Ma, Fuyin; Liu, Chongrui; Yuan, Xiao; Sun, Yangbin

doi:10.1016/j.apacoust.2022.109166

Cited by 1 publication

(1 citation statement)

References 35 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…Figure 3(c) shows the arrangement of the microphone atmeasuring point p e1 with an nosecone imitated from B&K to reduce the flow-induced tones, whose basic characteristics are equivalent to that of B&K nosecone from the performance test [37], and the acoustic pressures at other measuring points can be measured by moving the microphone according to a similar method. As shown in figure 3(d), a square-section air duct with a length, width and height of 2900 mm, 900 mm and 900 mm is arranged in the middle of the test section [38]. The Ahmed sample with LFSHR metasurface is fixed on an 8Llong (L = 261 mm) and 20 mm-thick grounding plate with a rounded leading edge to prevent flow separation, which is installed 100 mm above the bottom wall of the wind tunnel to simulate the influence of the ground shear layer and extends between the two side walls of the wind tunnel.…”

Section: Verification Of the Broadband Aerodynamic Noise Reduction Wi...mentioning

confidence: 99%

Aerodynamic noise control with an acoustic metasurface comprising an array of low-flow-sensitivity Helmholtz resonators

2023

Phys. Scr.

Self Cite

View full text Add to dashboard Cite

We report the design, simulation, and experimental testing of an acoustic metasurface made from an array of low-flow-sensitivity Helmholtz resonators (LFSHRs). The low flow-sensitivity of sound attenuation reflects two aspects, one is the low sensitivity of the impedance peak magnitude that is attributed to the increase of the flow velocity at the interface resulted from the stronger vortexes inside the multilayer-hole neck, and the other is the low sensitivity of the impedance peak frequency due to the increased acoustic mass from the strengthened cavity-main flow interaction. Using this metasurface, the increment of both the magnitude and frequency of the impedance peak caused by the increasing fluid flow could be reduced by more than 70.5% and 93.8% respectively compared with a Helmholtz resonator (HR), and could be further minimized by parameter optimization. This low-flow-sensitivity acoustic metasurface proposed has great potential applications for aerodynamic noise control.

show abstract

Section: Verification Of the Broadband Aerodynamic Noise Reduction Wi...mentioning

confidence: 99%

An ultra-thin low-frequency broadband metasurface with near-zero suppression of aerodynamic acoustic pressure

Cited by 1 publication

References 35 publications

Aerodynamic noise control with an acoustic metasurface comprising an array of low-flow-sensitivity Helmholtz resonators

Aerodynamic noise control with an acoustic metasurface comprising an array of low-flow-sensitivity Helmholtz resonators

Contact Info

Product

Resources

About