Finite amplitude distortion and dispersion of a nonplanar mode in a waveguide
Finite amplitude distortion and dispersion of a nonplanar mode in a waveguide
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DOI：
10.1121/1.393914
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发表时间：
1986-09
影响因子：
2.4
通讯作者：
J. Ginsberg;H. Miao
中科院分区：
文献类型：
--
作者：
J. Ginsberg;H. Miao
本文用重正化微扰法研究了非线性对硬壁矩形波导的影响。如果系统是线性的，激励只会产生基本的非平面对称模。分析开发了一个解决方案，满足非线性波动方程的速度势，以及所有的边界条件。响应由一对倾斜平面波组成，它们通过真实平面模式的二阶激励相互作用。研究表明，在高频极限下，信号具有准平面行为。相反，对于超过截止值的非常低的频率，斜波基本上是独立的。这种扭曲是自折射的结果，其中粒子运动使波前和光线移动。低频和高频极限之间的过渡以非线性频率色散的出现为标志，这会产生波形的不对称失真。
The perturbation method of renormalization is used to study the effect of nonlinearity on a hard‐walled rectangular waveguide. The excitation would induce only the fundamental nonplanar symmetric mode if the system were linear. The analysis develops a solution that satisfies a nonlinear wave equation for the velocity potential, as well as all boundary conditions. The response consists of a pair of oblique planar waves that interact through second‐order excitation of the true planar mode. The investigation discloses that in the high‐frequency limit the signal has a quasiplanar behavior. In contrast, for very low frequencies exceeding the cutoff value, the oblique waves are essentially independent. The distortion is then a result of self‐refraction, in which the particle motion shifts the wave fronts and rays. The transition between the low‐ and high‐frequency limits is marked by the appearance of nonlinear frequency dispersion, which produces asymmetrical distortion of the waveform.