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共振吸声器作为消声覆盖层,被广泛地应用于水下。本文在Galerkin技术基础上,用有限元法分析垂直入射平面波穿透共振吸声器时的反射特性。用波导理论,连同流体中的阻抗匹配条件模拟该问题。本文说明吸声器周围的流体介质可以被模拟成一种具有等效拉梅常数的弹性介质。利用在周期单元中四分之一对称条件。把有限元法得出的结果和分析法得出的结果,以及与其它文献上发表的结果进行比较。该方法表明,如果透射系数或反射系数仅为通常条件,就可避免与流体区域搅合在一起。最后,本文提供了一些薄型水封共振吸声器的设计曲线。
Resonance sound absorber as muffler cover, is widely used in underwater. Based on the Galerkin technique, the finite element method is used to analyze the reflection characteristics of a normal incident plane wave penetrating a resonant sound absorber. This problem is simulated with waveguide theory, along with impedance matching conditions in the fluid. This paper shows that the fluid medium around the absorber can be modeled as an elastic medium with an equivalent Lame constant. Take advantage of quarter-symmetric conditions in the periodic unit. The results obtained by the finite element method and the results obtained by the analytical method are compared with those published in other literatures. This method shows that mixing with the fluid zone can be avoided if the transmission coefficient or reflectance is only normal conditions. Finally, this article provides some design curves for thin, water-sealed resonant sound absorbers.