A method for obtaining the sound transmission rate and sound transmission loss of circular openings

Abstract

The invention discloses a method for obtaining a sound transfer rate and a sound transmission loss of a circular opening. The method is characterized by firstly defining a coordinate system of the circular opening, establishing force balances at cross sections of two sides of the opening and sound transfer matrixes at two ends of the opening, and calculating the sound transfer rate of a single-step mode state of the circular opening under parallel sound wave incident conditions by using properties of sound radiation impedance of air layer vibration at the two ends of the opening, superimposing sound transfer rates of different step mode states to obtain the sound transfer rate of the circular opening, integrating an angle of incidence to obtain the sound transfer rate of the circular opening under incident conditions of a scattering sound field, finally obtaining the sound transfer loss of the circular opening under the incident conditions of the scattering sound field through a relation of the sound transmission loss and the sound transfer rate. According to the invention, the sound transfer rates or the sound transfer losses of a certain step or multiple steps can be respectively calculated, and the total sound transfer rate or sound transmission loss can be further calculated to greatly improve the calculation flexibility. Influences of the sound radiation impedance of a real part and an imaginary part which are both small are partly ignored to greatly improve the computing speed.

Description

technical field [0001] The invention relates to a method for obtaining the sound transmission rate and sound transmission loss of a circular opening on a wall in the field of noise in the specialty of physics, in particular to a method capable of obtaining a circular cross-sectional shape of the boundary on both sides of the opening on the wall The acoustic transmission rate and acoustic transmission loss method of openings with limited depth and need to consider high-order wave components (high-order modes need to be considered). Background technique [0002] Openings are mainly divided into large openings, small and medium holes, and micropores. [0003] For micropores, academician Ma Dayou, a famous Chinese scholar, and his research team have conducted in-depth research, and many domestic and foreign scholars have also conducted a lot of research. [0004] For small and medium holes, because their size is not very large, the frequency range of the research is often below...

AI Technical Summary

Problems solved by technology

[0006] These methods have certain effects and have their own characteristics when calculating specific types of openings, but they also have certain limitations

For example, the acoustic transmission loss calculation formula derived based on the plane wave theory can only be used to calculate the acoustic transmission loss below the cutoff frequency of the plane wave

Although the modal-based acoustic transmission loss calculation formula can calculate the total acoustic transmission rate and acoustic transmission loss, it cannot calculate the acoustic transmission rate and acoustic transmission loss of the opening in any one or multiple modes, and when the frequency is very High, when the number of modes is large, the calculation speed is slow

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