Broadband High Efficiency Muffler Tube Structure Based on Non-Bragg Resonance

Abstract

The broadband high-efficiency muffling tube structure based on non-Bragg resonance is characterized in that the tube wall of the tubular muffling tube undulates periodically, and the undulating change of each cycle means that the inner wall of the tube is composed of adjacent concave-convex ring-shaped undulations, each change The width of the period is equivalent to the size of the average radius of the muffler tube, the frequency of the incident wave is audible, and the mode and direction of the incident wave are arbitrary; the muffler tube contains more than 5 periods. By changing the parameters of the periodic tube wall, such as the number of periods, the size of undulations, etc., the muffler volume of the muffler can be controlled. Through the selection of its pipe wall period, the anechoic frequency band can be changed according to actual engineering needs. In practical engineering applications, it can also be combined with other resistive noise reduction methods to improve the sound absorption effect. Furthermore, this structure can also be used as an acoustic filter.

Description

technical field [0001] The invention relates to the band structure theory of the periodic waveguide, in particular to a pipeline muffler based on the non-Bragg resonance phenomenon. Background technique [0002] The problem of fluctuations in periodic waveguides has attracted extensive attention for a long time. The most classic research work in acoustics can be traced back to 1887. Rayleigh studied the propagation of sound waves in thin strings with periodic density changes, derived the propagation equation, and used the Hill method to study the solution of the equation. Until the 1970s, the rapid development of mathematical theory and calculation methods greatly promoted the research work in this area, and the propagation of sound waves and electromagnetic waves in periodic waveguides received extensive attention and in-depth research. [0003] In 1974, Nayfeh used the multi-scale expansion method to obtain the effective consistent expansion near the resonance region of t...

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Problems solved by technology

[0009] The purpose of the present invention is: in order to solve the problem of poor controllability of the noise reduction frequency band and noise reduction effect in the general noise reduction pipe, the present invention breaks through the limitation of the traditional expansion pipe silencer, and proposes a wide noise reduction bandwidth based on the non-Bragg resonance mechanism Muffler structure

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