ON THE RADIATION OF SOUND FROM AN UNFLANGED CIRCULAR PIPE
ON THE RADIATION OF SOUND FROM AN UNFLANGED CIRCULAR PIPE
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DOI：
10.1103/physrev.73.383
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发表时间：
1948-01-01
期刊：
影响因子：
--
通讯作者：
SCHWINGER, J
中科院分区：
文献类型：
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作者：
LEVINE, H;SCHWINGER, J
在轴对称激励条件下，得到了无法兰圆管声辐射问题的精确解。该解在平面波在管道中传播的整个波长范围内都是有效的。对管道内速度势的反射系数和反映辐射方向图特征的功率增益函数进行了数值计算。结果表明，管道对来自外部空间的平面波的吸收截面和该方向的增益函数满足互易关系。特别地，法向入射的吸收截面正好是口的面积。在低频振动下，管道内的速度势与管道延长一定比例的半径相同，并且开口端表现为环路。最终修正的确切值是0.6133。
A rigorous and explicit solution is obtained for the problem of sound radiation from an unflanged circular pipe, assuming axially symmetric excitation. The solution is valid throughout the wave-length range of dominant mode (plane wave) propagation in the pipe. The reflection coefficient for the velocity potential within the pipe and the power-gain function, embodying the characteristics of the radiation pattern, are evaluated numerically. The absorption cross section of the pipe for a plane wave incident from external space, and the gain function for this direction, are found to satisfy a reciprocity relation. In particular, the absorption cross section for normal incidence is just the area of the mouth. At low frequencies of vibration, the velocity potential within the pipe is the same as if the pipe were lengthened by a certain fraction of the radius and the open end behaved as a loop. The exact value of the end correction turns out to be 0.6133.