Numerical evaluation of the Rayleigh integral for planar radiators using the FFT
Numerical evaluation of the Rayleigh integral for planar radiators using the FFT
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DOI：
10.1121/1.388633
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发表时间：
1982-12
影响因子：
2.4
通讯作者：
E. Williams;J. Maynard
中科院分区：
文献类型：
--
作者：
E. Williams;J. Maynard
利用快速傅立叶变换算法对任意形状的平面辐射体在源平面上具有任意指定速度的瑞利积分公式进行了数值计算。这种技术的主要优点是它的计算速度——比直接的二维数值积分快400多倍。该技术是为计算源近场的辐射压力而开发的，并且可以很容易地扩展到提供近场的矢量强度，计算时间很少。用FFT计算夹紧边界和自由边界的折板矩形板的近场压力，并与“精确”解进行了比较，以说明任何误差。研究了由FFT引入的偏置误差，并开发了一种显著减小偏置误差的技术。
Rayleigh’s integral formula is evaluated numerically for planar radiators of any shape, with any specified velocity in the source plane using the fast Fourier transform algorithm. The major advantage of this technique is its speed of computation—over 400 times faster than a straightforward two‐dimensional numerical integration. The technique is developed for computation of the radiated pressure in the nearfield of the source and can be easily extended to provide, with little computation time, the vector intensity in the nearfield. Computations with the FFT of the nearfield pressure of baffled rectangular plates with clamped and free boundaries are compared with the ‘‘exact’’ solution to illuminate any errors. The bias errors, introduced by the FFT, are investigated and a technique is developed to significantly reduce them.