Bias current double-layer perforated plate sound absorption device with adjustable back cavity depth

A technology of sound-absorbing device and porous plate, which is applied in the direction of sound-emitting devices and instruments, can solve the problems of narrow sound-absorbing frequency band and poor sound-absorbing performance of non-flow porous plate sound absorbers, and achieves easy processing and manufacturing and good sound-absorbing effect , to ensure the effect of safe operation

Active Publication Date: 2020-11-06
ZHEJIANG UNIV
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  • Abstract
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Problems solved by technology

[0006] The technical problem to be solved by the present invention is that the effective sound absorption frequency band of the porous plate is narrow at present, and the sound absorption frequency band cannot be adjusted according to the sound wave characteristics of the incident noise, and the sound absorption performance of the non-flow porous plate sound absorber is poor

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  • Bias current double-layer perforated plate sound absorption device with adjustable back cavity depth
  • Bias current double-layer perforated plate sound absorption device with adjustable back cavity depth
  • Bias current double-layer perforated plate sound absorption device with adjustable back cavity depth

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Embodiment Construction

[0036]In the following description, many specific details are set forth in order to fully understand the present invention, but the present invention can also be implemented in other ways different from those described here, therefore, the present invention is not limited to the specific embodiments disclosed below limit.

[0037] Embodiments of the present invention are described in detail below, examples of which are shown in the drawings, wherein the same or similar reference numerals designate the same or similar elements or elements having the same or similar functions throughout. The embodiments described below by referring to the figures are exemplary and are intended to explain the present invention and should not be construed as limiting the present invention.

[0038] refer to figure 1 and figure 2 , The bias flow double-layer porous plate sound-absorbing device in this embodiment includes an air inlet pipe section 3, one end of the air inlet pipe section 3 is pro...

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Abstract

The invention discloses a bias current double-layer perforated plate sound absorption device with adjustable back cavity depth. The device comprises an air inlet pipe section, a movable piston with anair inlet is arranged at one end of the air inlet pipe section, an exhaust port is formed in the other end of the air inlet pipe section, an air inlet upstream pore plate and an air inlet downstreampore plate are sequentially arranged in the air inlet pipe section in the air inlet direction, and micropores are formed in the air inlet upstream pore plate and the air inlet downstream pore plate inan array mode; a first-stage cavity with the adjustable depth is formed between the movable piston and the air inlet upstream pore plate, a second-stage cavity is formed between the air inlet upstream pore plate and the air inlet downstream pore plate, and the two stages of cavities form an intra-cavity sound absorption structure. According to the invention, the sound absorption performance of the pore plate under bias current is obviously improved compared with that of the pore plate without current; by use of the double-layer perforated plate, the sound absorption frequency band is widened,the device can be used for eliminating noise generated by unstable combustion in the combustor, the service life of equipment is prolonged, and the safety of the equipment is improved.

Description

technical field [0001] The invention relates to the field of noise control based on porous sound absorption, in particular to a bias flow double-layer porous plate sound absorption device with adjustable back cavity depth. Background technique [0002] Research and control of radiated noise is an urgent need to reduce environmental noise and protect the stable operation of production equipment. Gas turbines with lean premixed combustion, aviation gas turbines, oil and gas boilers, and combustion noises are likely to be generated due to unstable combustion. These self-excited noises from thermoacoustic coupling will cause combustion system vibration, control system failure, combustion equipment damage or use Reduced lifespan. The pressure fluctuation in the intake section of the burner has an important influence on the self-initiation and maintenance of combustion instability. [0003] Ma Dayou, a well-known acoustic expert in my country, has conducted detailed research on ...

Claims

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Application Information

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Patent Type & Authority Applications(China)
IPC IPC(8): G10K11/16G10K11/168
CPCG10K11/168G10K11/16Y02T90/00
Inventor 周昊刘子华
Owner ZHEJIANG UNIV
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