Acoustic eigenfrequencies of cavities with an internal obstacle: A modified perturbation theory
Acoustic eigenfrequencies of cavities with an internal obstacle: A modified perturbation theory
复制标题
具有内部障碍的空腔的声学特征频率：改进的微扰理论
DOI：
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发表时间：
1989
期刊：
影响因子：
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通讯作者：
R. Hill
中科院分区：
文献类型：
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作者：
J. Mehl;R. Hill
硬壁声腔谐振器的本征频率通过求解具有Neumann边界条件的Helmholtz方程来找到。考虑了一个空腔C，其内部有一个尺寸为零的硬障碍物B。由于扰动在障碍物附近永远不小，即使在小障碍物的极限内也是如此，因此需要一种修正的扰动理论。通过计算轴上有一个内球的圆柱体的本征频率，发展了一种形式并进行了检验。与其他研究人员确定的理论和实验值的结果进行了比较。微扰计算和数值结果之间的差异从小于未微扰本征频率的10−5到大约0.02不等，这取决于微扰球的大小和模式。
The eigenfrequencies of a hard‐walled acoustic cavity resonator are found by solving the Helmholtz equation with Neumann boundary conditions. A cavity C with an internal hard obstacle B of vanishing size was considered. Because the perturbation is never small in the neighborhood of the obstacle even in the limit of a small obstacle, a modified perturbation theory is required. A formalism was developed and tested by calculating the eigenfrequencies of a cylinder with an internal sphere on the axis. The results are compared with theoretical and experimental values determined by other investigators. The difference between the perturbation calculations and the numerical results varies from less than 10−5 to about 0.02 of the unperturbed eigenfrequency, depending on the size of the perturbing sphere and the mode.