抗性消声器单元气流二次噪声的仿真分析

Simulation Analysis of the Regeneration Noise of Reactive Muffler Unit

为探讨气流在抗式消声器中产生的二次噪声随流速以及结构参数的变化规律,采用ANSYS Fluent与Virtual.Lab Acoustics联合仿真来求解简单消声器单元的气流二次噪声,并与实验结果比较,验证了其可靠性。分析了结构因素和气流速度对几种基本的消声器单元的气流二次噪声的影响规律,研究了过渡的收缩结构和进出口不同轴对二次噪声的影响。结果表明:扩张式、插入管式和穿孔板式消声单元气流二次噪声随气流速度增大而增大,但穿孔管消声单元在流速达到一定值后出现下降;增大简单扩张式消声单元的扩张比、扩张腔长度、进口管内径以及使进出口管同轴和采用过渡圆角有助于降低二次噪声;插入管插入的长度、穿孔板孔径的减小、穿孔板距入口截面突变处距离的增大以及壁厚的增加都有助于减小气流二次噪声;穿孔管孔径的减小、轴向穿孔排数和每排穿孔数量的减小均有助于减小二次噪声。

In order to explore the regulation of the noise produced by the airflow in the reactive muffler when airspeed and structure factors changed,this study got the regeneration noise by joint simulation of ANSYS Fluent and Virtual. Lab Acoustics,compared the result with experimental results to verify its reliability. It analyzed the influence of the structural factors and velocity of the airflow for the regeneration noise of several basic muffler unit,and studied the airflow regeneration noise when using the contraction structural transition and when inlet and outlet located in the different axis. Theresults showed that airflow regeneration noise of the expansion type,insert tube type and perforated plate type muffler element increases with the flow velocity,but the perforated pipe muffler＇s airflow regeneration noise decline when velocity reaches a certain value; Increasing the simple expansion muffler unit＇s expansion ratio,the length of expanding cavity,inlet tube diameter,setting the inlet and outlet in the same axis or design a arc transition structure can reduce the regeneration noise.Reducing the insert tube insertion length and the aperture of the perforated plate,and increasing the distance from the entrance expansion to the perforation plate and the wall thickness of the perforated plate can also reduce the regeneration noise. Reducing the perforated pipe diameter,the axial perforated rows and each row number of perforation are helpful to reduce the regeneration noise.