Abstract A method to analyze the acoustic characteristics of periodic structures is investigated. When a continuous boundary condition is introduced, the field in which a plane wave is normally incident on the periodic structure can be easily analyzed by the finite-difference time-domain (FDTD) method. However, when a plane wave source is obliquely incident, field mapping with auxiliary variables is necessary to remove the phase shift between unit cells. Here, a technique originally proposed for an electromagnetic field is applied to a sound field. The effects of the geometric parameters of the periodic structures on the sound pressure distribution and transmission loss in the mapped sound field are shown. This technique is validated by comparing the results with those in a field solved with the classical FDTD scheme. The dispersion relation and the stability condition for the time interval of the FDTD method for each incident angle of the plane wave in the mapped field are studied.

中文翻译：

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用有限差分时域法分析声场中周期性结构的斜入射

摘要 研究了一种周期性结构声学特性的分析方法。当引入连续边界条件时，平面波垂直入射到周期性结构上的场可以很容易地通过有限差分时域 (FDTD) 方法进行分析。然而，当平面波源倾斜入射时，需要使用辅助变量进行场映射以消除晶胞之间的相移。这里，最初为电磁场提出的技术被应用于声场。显示了周期性结构的几何参数对映射声场中声压分布和传输损耗的影响。通过将结果与使用经典 FDTD 方案求解的场中的结果进行比较，验证了该技术。