Broadband muffler pipe of adjustable resonant frequency based Helmholtz resonator

A resonant frequency, resonator technology, applied in the field of broadband muffler pipes, to achieve the effect of thickness reduction

Inactive Publication Date: 2016-12-07
NANJING UNIV
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  • Summary
  • Abstract
  • Description
  • Claims
  • Application Information

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Problems solved by technology

However, the cavity length of this kind of resonator is usually much smaller than the wavelength of the sound wave, and the resonant frequency obtained

Method used

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  • Broadband muffler pipe of adjustable resonant frequency based Helmholtz resonator
  • Broadband muffler pipe of adjustable resonant frequency based Helmholtz resonator
  • Broadband muffler pipe of adjustable resonant frequency based Helmholtz resonator

Examples

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Embodiment

[0029] Example: such as Figure 4 with Figure 5 As shown, in the present invention, a Helmholtz resonator with an adjustable resonance frequency is used to realize a wide-band noise reduction pipeline, and the cavity 3 with the same structural size and the throat 4 with different eccentricity and cross-sectional area are symmetrically installed on the upper and lower surfaces respectively. , The change of the eccentricity and cross-sectional area of ​​the throat pipe 4 is realized by moving the solid baffle 2 left and right. On this basis, resonators with different structural parameters are cascaded, and six cavities 3 of the same size are symmetrically distributed on the upper and lower surfaces of a main pipe 1, a total of 12 resonators with different resonance frequencies. The length of the main pipe 1 is about 700mm, the height is 50mm, the length and height of the cavity 3 are: 83.3mm, 12mm, the height of the throat 4 is 2mm, the cross-sectional length and the distance ...

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PUM

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Abstract

The invention discloses a broadband muffler pipe of adjustable resonant frequency based Helmholtz resonator. The pipe comprises an upper surface and a lower surface arranged on the pipe body in a parallel manner. The upper surface and the lower surface are both provided with a plurality of dimensionally fixed cavities arranged symmetrically along the main pipe body with the cavities at equal intervals. A pair of solid baffle plates is arranged between each cavity and the main pipe body. A throat tube with variable positions and cross-sections is formed between two solid baffle plates. The eccentricity and the cross-section of the throat tube vary according to the movement of the solid baffle plates from the left to the right. The broadband muffler pipe of adjustable resonant frequency based Helmholtz resonator of the invention can improve the cavity length without changing the volume of the resonator cavity so that the size of the cavity on the acoustic wave transmission path is close to an acoustic wave length. With the invention, the action frequency of the resonator is changed by breaking the application conditions of a lumped parameter system and changing the cross-section size of the internal throat tube and its distance to the center of the cavity.

Description

technical field [0001] The invention relates to a wide-band muffler pipeline based on a Helmholtz resonator with adjustable resonance frequency, and belongs to the field of acoustics. Background technique [0002] Traditional pipeline noise reduction equipment such as the Helmholtz resonator pipeline based on resonance noise reduction is equivalent to a resistant silencer, consisting of a throat and a cavity. The air in the throat is equivalent to the sound quality, and the cavity is equivalent to the spring, which are respectively analogous to the inductance and capacitance in the electrical circuit. When the sound wave frequency is closest to the natural frequency of the muffler, the noise reduction is the largest, and it acts as an acoustic filter. However, the cavity length of this kind of resonator is usually much smaller than the wavelength of the sound wave, and the resonant frequency obtained by treating it as a concentrated parameter does not change with the size. ...

Claims

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Application Information

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IPC IPC(8): G10K11/16
CPCG10K11/16
Inventor 梁彬杨京张海龙邹欣晔程建春
Owner NANJING UNIV
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