中文摘要：

在消声器的设计过程中,消声器流阻与消声量是一对矛盾.为解决这一问题,并使消声器能够适应不同工况下的消声需求,设计了一种可以根据消声器流阻大小改变内部结构,从而改变消声器内部空气流动模式的半主动阻抗复合式消声器.以基于椭圆柱坐标系的三维分析法为理论依据计算了该消声器两种不同结构下的消声量,并在驻波管实验系统中对计算结果进行了实验验证.结果表明,通过切换结构能够在大大减小流阻的情况下保证一定的消声量,从而实现消声量对不同工况的适应性.

英文摘要：

The flow resistance and the acoustic attenuation of the muffler are in contradiction during the designing process. To solve this problem, and to make the muffler adaptive to the varying working conditions, a kind of semi-active impedance compound muffler that is able to change the airflow mode by changing the inner-structure according to the flow resistance is designed. The acoustic attenuation perfarmance of the muffler with two different inner-structures is calculated on the basis of three-dimensional analysis method based on elliptical cylindrical coordinates, and then the result is tested through experimental verification on impedance tube. The result shows that the muffler is able to provide a relatively high acoustic attenuation with low flow resistance, and thus providing adaptability to different working conditions.