Helmholtz resonators with more than one opening

Dosch, H. G.; Hauck, Matthias

doi:10.1088/1361-6404/ac3098

Cited by 1 publication

(1 citation statement)

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“…However, the increased NPPA in the DMP‐PCW structure increases the open area of the main pores, while acoustic radiation interference between the cell wall pores changes the acoustic impedance of the resonant cavity, leading to the weakening of the resonant behavior. [ 49 ] This results in a decrease in the total sound pressure amplitude and the absorption of sound energy at the resonant peak frequency (1850 Hz) decreases.…”

Section: Resultsmentioning

confidence: 99%

Sound Absorption Performance and Mechanism of Aluminum Foams with Double Main Pore‐Porous Cell Wall Structure

Huang

Zuo

et al. 2023

Adv Eng Mater

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To enhance the sound absorption performance of open‐cell aluminum foam, the double main pores‐porous cell walls (DMP‐PCW) aluminum foams via infiltration casting of preforms mixed with two sizes of NaCl particles are prepared. The pore structure, sound absorption performance, and mechanism of DMP‐PCW aluminum foam are investigated. The pore structure consists of double‐sized main pores similar to the NaCl particles and the cell wall pores formed by the connections between NaCl particles. It is found that the static flow resistivity of DMP‐PCW aluminum foam reaches an optimum value of 28105 Pa.s m−2 when the volume proportion of small main pores increases, the size of cell wall pores decreases, and the number of cell wall pores per unit main pore surface area (NPPA) increases. At 800–6300 Hz, the average absorption coefficient is 0.89. In addition, the Wilson model predicts the sound absorption properties of DMP‐PCW aluminum foam. The predicted values agree well with the measured values. The finite‐element acoustic simulations and dynamic viscous‐thermal permeability calculations reveal that the improved sound absorption performance of DMP‐PCW aluminum foam is correlated to the enhanced sound transmission caused by increased NPPA and increased viscous‐thermal loss due to the double main pore structure.

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Section: Resultsmentioning

confidence: 99%