39results about How to "Improve low-frequency sound absorption performance" patented technology

The present application relates to a kind of multi-channel acoustic black hole sound absorption structure and silencer, belong to noise control technical field, the defects of current acoustic black hole sound absorption structure are solved, including shell, the side of shell is open, the open side of shell is used to receive incident sound wave, partition is equipped in shell to separate the space in shell into multiple sound absorption channels, multiple rib plates are equipped in each sound absorption channel, the outer end of rib plate is fixed with the inner side of shell, rib plate is perpendicular to the incident direction of sound wave, multiple rib plates are spaced along the incident direction of sound wave, and along the incident direction of sound wave, the width of multiple rib plates gradually increases, the inner end of multiple rib plates is set power law function distribution, the inner end of multiple rib plates is bonded with the outer side of porous plate and is fixedly connected with porous plate, the sound absorption structure of the present application can better realize ultra-wideband sound absorption.

The invention belongs to the technical field of acoustic metamaterials, and discloses an acoustic metamaterial silencing structure and a preparation method thereof. The structure comprises a microwell plate structure layer, a porous material structure layer and an acoustic metamaterial unit array structure layer, the microwell plate structure layer is provided with a first sound absorption channel group, and the microwell plate structure layer is closer to the sound source side than the porous material structure layer; the porous material structure layer is provided with a second sound absorption channel group; the acoustic metamaterial unit array structure layer is arranged between the microplate structure layer and the porous material structure layer and comprises a silencing unit group, the silencing unit group comprises a plurality of silencing units which are arranged in the circumferential direction, the silencing units define a silencing cavity, neck channels are arranged on the side walls, facing the silencing cavity, of the silencing units in a protruding mode, and the neck channels are communicated with the silencing cavity. The silencing cavity is communicated with the first sound absorption channel set and the second sound absorption channel set through the neck channel, the inner wall face of the neck channel is limited to form a sound absorption face so that sound wave energy entering and exiting the silencing cavity can be reduced, and the purposes of silencing and noise reduction are achieved while the weight is light.