Bidirectional rough inner insertion tube type Helmholtz resonance sound absorption structure

A technology of resonant sound absorption and intubation, which is applied in the direction of sound-emitting devices and instruments, and can solve the problems of poor low-frequency sound absorption, difficulty in light weight, and difficulty in manufacturing, so as to improve acoustic impedance characteristics and enhance low-frequency Sound-absorbing characteristics and the effect of ensuring load-carrying capacity

Pending Publication Date: 2021-09-07
XI AN JIAOTONG UNIV
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  • Summary
  • Abstract
  • Description
  • Claims
  • Application Information

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Problems solved by technology

[0003] The technical problem to be solved by the present invention is to provide a two-way rough inner tube-type Helmholtz resonance sound-absorbing structure to solve the low-frequency sound-absorbing effect commonly found in air-borne sound-absorbing structures in the past. Poor quality, narrow effective sound absorption bandwidth, difficult manufacturing, large structural size and difficulty in light weight

Method used

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  • Bidirectional rough inner insertion tube type Helmholtz resonance sound absorption structure
  • Bidirectional rough inner insertion tube type Helmholtz resonance sound absorption structure
  • Bidirectional rough inner insertion tube type Helmholtz resonance sound absorption structure

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Embodiment

[0051] Examples of materials:

[0052] Alloy steel: characterized by a density of 7820kg / m 3 , Young's modulus 206GPa, Poisson's ratio 0.29.

[0053] Air: characterized by a density of 1.29kg / m 3 , sound velocity 343m / s, dynamic viscosity coefficient 1.81×10 -5 Pa·s.

[0054] Structural dimensions and material selection of comparative examples:

Embodiment 1

[0063] The diameter of the cavity is 20mm, the height of the cavity is 20mm, the average inner radius of the two-way rough inner tube is 1.5mm, the axial relative roughness of the two-way rough inner tube is 0.15, the axial wave number of the two-way rough inner tube is 0.5π, and the circumference of the two-way rough inner tube is The relative roughness is 0.1, the circumferential wave number of the two-way rough inner tube is 8, and the length of the two-way rough inner tube is 15mm.

Embodiment 2

[0065] The diameter of the cavity is 24mm, the height of the cavity is 30mm, the average inner radius of the two-way rough inner cannula is 2mm, the axial relative roughness of the two-way rough inner cannula is 0.25, the axial wave number of the two-way rough inner cannula is π, and the circumferential direction of the two-way rough inner cannula is relative The roughness is 0.15, the circumferential wave number of the two-way rough inner tube is 3, and the length of the two-way rough inner tube is 20mm.

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Abstract

The invention discloses a bidirectional rough inner insertion tube type Helmholtz resonance sound absorption structure, which is characterized in that the height of a cavity is 20-50 mm, the diameter of the cavity is 20-30 mm, the upper surface of the cavity is provided with a small hole, a bidirectional rough inner insertion tube is arranged in the small hole, the bidirectional rough inner insertion tube is connected with the cavity in a gluing or welding mode, the lower surface of the cavity is fixed on the surface of an object needing acoustic treatment, a bidirectional rough inner insertion tube type Helmholtz resonance sound absorption structure is formed, and the sound absorption coefficient at the frequency of 100-500 Hz is larger than 0.99. The bidirectional rough inner insertion tube type Helmholtz resonance sound absorption structure has excellent low-frequency-band sound absorption performance, good bearing capacity and a light-weight overall structure; and in the aspect of design, more adjustable and controllable structure geometric parameters are achieved, optimization adjustment can be conducted according to actual scene requirements, the structure is simple, and manufacturing and assembling are convenient.

Description

technical field [0001] The invention belongs to the technical field of air sound absorption, and in particular relates to a two-way rough inner tube type Helmholtz resonance sound absorption structure. Background technique [0002] As the impact of low-frequency noise on human production and life continues to expand, its effective absorption has attracted more and more attention. The traditional Helmholtz resonance sound-absorbing structure is composed of a micro-perforated plate and an air-backed cavity. Through the vibration of sound waves in the cavity, the sound energy is absorbed to achieve the effect of sound insulation and noise reduction. Its application scenarios include but are not limited to Equipment and facilities for film and television theaters, hotel halls, and airplanes, trains, etc. The traditional micro-perforated plate Helmholtz resonance sound-absorbing structure has poor noise absorption ability in the low frequency band. It is necessary to increase th...

Claims

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Application Information

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IPC IPC(8): G10K11/162G10K11/172
CPCG10K11/162G10K11/172
Inventor 辛锋先张磊
Owner XI AN JIAOTONG UNIV
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