Broadband sound absorption structure design method based on quadratic residue sequence

Abstract

The invention discloses a broadband sound absorption structure design method based on a secondary residual sequence, and the method comprises the steps: selecting a working frequency through the secondary residual sequence, carrying out the structural parameter adjustment of a sound absorption unit cell, building a coupling structure, and achieving the purpose of broadband sound absorption. A simulation result shows that the average sound absorption rate in a 200-1200Hz frequency domain range can be 0.56, i.e., the noise in a full frequency domain range is reduced by more than half. Compared with an existing linear sequence, the sound absorption peak value is high, and the sound absorption frequency band is wider.

Description

Technical field [0001] The present invention belongs to the field of avionics noise reduction and sound absorption technique, and in particular, the present invention relates to a wide-frequency sound absorbing structure design method based on secondary residual sequence. Background technique [0002] The noise issued by combat aircraft takes off and landing will cause chronic damage to the physical and mental health of the operating personnel in the base, causing the mood low, insomnia, deafness, etc., and even shorten the life, and seriously affect the combativity. With the maintenance of the domestic remote blow, early warning machine, anti-submarine patrol machine and strategic transport machine, the task of the large-air domain has gradually increased, the engine noise in the long-term flight of the driver and other airborne person's spirit and physiological health Be serious. Therefore, it is of great significance to reduce the operation of the aircraft to maintain the work...

AI Technical Summary

Problems solved by technology

[0005] Traditional acoustic lining structures such as perforated panels have a narrow sound absorption frequency band and weak low-frequency insertion loss due to their non-adjustable uniform structure and the inherent characteristics of the through-air back cavity. At the same time, the thickness of the perforated panel structure is equivalent to the wavelength of the operating frequency. Further hinder its application prospects in the field of low-frequency noise reduction

In addition, the traditional micro-perforated board honeycomb acoustic lining structure has huge differences in the sound absorption efficiency and sound absorption frequency of incident sound waves in different directions, so that the design of fluid machinery must be considered comprehensively in the design of the acoustic lining structure and coverage area, which further increases the The design difficulty of the acoustic lining structure

In addition, although in recent years, researches on sound absorbers based on acoustic metamaterials have emerged in an endless stream. For example, thin-film resonators and Helmholtz resonators can obtain good sub-wavelength low-frequency sound absorption effects, but the sound absorption frequency band is narrow.

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