轴向对称小夹角分支隧道中电磁波传输特性

Propagation characteristic of electromagnetic waves in circular mine tunnel whit symmetric branch of small axial angle

采用弯曲柱面坐标系研究了轴向对称且夹角较小的分支隧道中电磁波传输特性,在分支隧道严格对称性的情况下,利用玻印亭定理从能量守恒的角度分析得到主隧道中电磁波能量平均地流入对称分支隧道中。根据空心介质波导衰减的定义,在隧道分支处不考虑隧道壁的劈型散射,得出分支隧道中的电磁波衰减与分支的轴向夹角的四次成正比例关系,并给出了电磁波低次模的实例计算和夹角与衰减常数的关系曲线。

This paper researches propagation characteristic of electromagnetic waves in circular mine tunnel whit symmetric branch and small axial angle in toroidal coordinate system. When the branch is strict symmetric in axis, the electromagnetic energy flow into the branch tunnel averagely according to energy conservation law by Poynting theorem. without considering wedge-scattering at joint of tunnel and branch, based on the attenuation definition of hollow dielectric wave guide a conclusion is drawn as follows electromagnetic wave attenuation in branch tunnel is in direct proportion to the quarter times of angle between tunnel and branch, and an example calculation about attenuation of low-order electromagnetic waves and graph of relation about angle and attenuation constant are expressed.