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Labyrinth resonator and pipeline silencing device based on same

A muffler device and resonator technology, applied in the direction of pipe elements, pipes/pipe joints/pipe fittings, mechanical equipment, etc., can solve the problems of narrow muffler frequency band, low resonance frequency, large space occupied, etc. The effect of bandwidth, reduced space, and high use value

Pending Publication Date: 2020-11-13
NANJING FORESTRY UNIV
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  • Summary
  • Abstract
  • Description
  • Claims
  • Application Information

AI Technical Summary

Problems solved by technology

The currently used quarter-wavelength tubes mainly have the following problems: (1) The quarter-wavelength tubes are usually arranged vertically with the intake pipe, and for low-frequency noise reduction, the required pipe is long and occupies a large space; (2) Because it is resonance noise reduction, the lower the resonance frequency, the narrower the noise reduction frequency band

Method used

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  • Labyrinth resonator and pipeline silencing device based on same
  • Labyrinth resonator and pipeline silencing device based on same
  • Labyrinth resonator and pipeline silencing device based on same

Examples

Experimental program
Comparison scheme
Effect test

Embodiment 1

[0046] Embodiment 1: Parallel connection of multiple labyrinth resonators 1 of the same size

[0047] The sound wave is incident along the direction of the main pipe, a 1 = 10cm, a2 =2cm, if n=4, then the actual length Ls of the centerline of the air channel of the labyrinth resonator 1=49cm, the end correction length δ=0.78cm, and the acoustic length L of the centerline of the air channel=49.78cm. If only one labyrinth resonator 1 is installed on one side of the main pipe, from Figure 8 It can be seen that its anechoic frequency band is very narrow; if four labyrinth resonators 1 of the same size are installed on the four side walls, it is equivalent to four resonators connected in parallel, Figure 8 Display anechoic bandwidth increased.

Embodiment 2

[0048] Embodiment 2: Series connection of multiple labyrinth resonators 1 with different sizes

[0049] Such as Figure 7 As shown, it is a series connection of multiple resonators with different air channel lengths, a 1 = 10cm, a 2 = 2cm, then the acoustic length of the center line of the air channel of the labyrinth resonator 1 is L 1 =49.78cm, L 2 =40.78cm,L 3 =32.78cm,L 4 =24.78cm; the numerical calculation results are as follows Figure 9 shown, from Figure 9 It can be seen that when multiple resonators are connected in series, noise in different frequency bands can be eliminated in a targeted manner.

Embodiment 3

[0050] Example 3: Noise reduction of an automobile engine air intake

[0051] Taking the automobile engine intake system as an example, the typical length of the air intake pipe is 0.6m, and the frequency corresponding to 1 / 4 wavelength is 140Hz, which is the ignition frequency of a 4-cylinder 4-stroke engine at 4200r / min. At the intake valve body of the engine, a labyrinth resonator 1 with the same length as the air duct is inserted. The acoustic length of the duct of the labyrinth resonator 1 is L=0.68m, which will produce stable transmission loss at 1 / 4 wavelength frequency. In order to cover a wider frequency, corresponding to the above engine 2000r / min~5000r / min (67Hz~167Hz), it is required to use a plurality of labyrinth resonators 1 with different air channel lengths, and the acoustic lengths of the pipes are 1.26m~0.51m respectively . At the opening of the engine intake duct, three labyrinth resonators 1 with different channel lengths are installed side by side, Fig...

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Abstract

The invention discloses a labyrinth resonator and a pipeline silencing device based on the labyrinth resonator. The labyrinth resonator is formed by sequentially and fixedly connecting a front panel,a labyrinth layer and a rigid back plate; a through hole is formed in the center of the front panel; the labyrinth layer comprises a frame and a plurality of partition plates which are located in theframe and are different in length, the partition plates are connected end to end to define a spiral shape, and labyrinth-shaped air channels are formed between the partition plates and between the partition plates and the frame; and the inlet of the labyrinth-shaped air channel is connected with the through hole of the front panel. The pipeline silencing device based on the labyrinth resonators comprises a main pipeline with a square cross section, four labyrinth resonators which are symmetrically distributed on the four side walls of the main pipeline and have the same air channel length, anda series of labyrinth resonators which are distributed on the side walls of the main pipeline in the axis direction of the main pipeline and have different air channel lengths, the labyrinth resonators are arranged in parallel and in series to achieve the purpose of low-frequency broadband noise elimination.

Description

technical field [0001] The invention relates to a pipeline muffler, in particular to a pipeline muffler based on a labyrinth resonator. Background technique [0002] Pipeline mufflers are widely used in automotive, aerospace and marine industries. There are many deficiencies in traditional resistive and resistive pipe mufflers. For example, the use of sound-absorbing materials in resistive mufflers can effectively control high-frequency noise, but it is difficult to control low-frequency noise, and it is not suitable for high temperature and unclean environments. Resistive mufflers usually adopt an expansion cavity structure and a branch pipe resonator structure, and are mainly used to control low and medium frequency noise. The branch tube resonator structure includes a Helmholtz resonator and a quarter-wavelength tube. The quarter-wavelength tube is a closed tube installed on the main tube. When the length of the tube is 1 / 4 of the wavelength of the incident sound wave ...

Claims

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Application Information

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Patent Type & Authority Applications(China)
IPC IPC(8): F16L55/033
CPCF16L55/033
Inventor 吴晓莉顾云风刘秀娟
Owner NANJING FORESTRY UNIV