| 摘要 |
The fine jet control type sound absorption system of this invention, aimed at absorbing low-frequency sound with both discrete frequency and broadband frequency to the same degree as already existing acoustic lining can do, is composed of two parts. One is a barrier wall covering an air space in which the concerning low-frequency sound propagates and having a multiplicity of small holes formed therein. The other is the means for causing a fine jet passing through these small holes into or out from the air space. This sound absorption system realizes a fine jet in the vicinity of the barrier wall for the purpose of canceling the sound inside the air space by means of the interference of the sound with the fine jets. Any of or a combination of shape of small holes, jet ejection angle or suction angle, amount of jet flow, thickness of a barrier wall back layer and air flow angle at which secondary air flows into the barrier wall back layer is selected.
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