The results of a modeling study for the numerical solution of the interior surface Helmholtz integral for acoustically lined curved pipes with rectangular cross-section are presented. The solution of the Helmholtz integral equation is calculated by using the boundary element method (BEM). The sound attenuation spectra of different possible models with regard to the lining on the boundaries are compared with the analytical solution. The acoustic behavior of different models is discussed and the features of the model that gives more accurate results are presented.

中文翻译：

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声学内衬弯管声衰减的边界元建模

给出了矩形横截面的声学内衬弯曲管道内表面亥姆霍兹积分数值解的建模研究结果。亥姆霍兹积分方程的解采用边界元法（BEM）计算。将边界上衬砌的不同可能模型的声衰减谱与解析解进行了比较。讨论了不同模型的声学行为，并给出了模型的特征，该模型给出了更准确的结果。