Non-Bragg reflections in a periodic waveguide

“…At the same time, the sharpness of corrugation will be considered as arbitrary. By separating in the potential (6a) its mean value and the term that oscillates about zero, V n (z) = V n (z) + ∆V n (z), under conditions (18) we have…”

Section: A the Trial Green Functionmentioning

confidence: 99%

“…By now, there has been a number of works on wave propagation in periodically corrugated waveguides (see, e. g., Refs. [15][16][17][18][19][20] and references therein). Many peculiarities of their spectra are studied in more detail.…”

Section: Introductionmentioning

confidence: 99%

The sharpness-induced mode stopping and spectrum rarefication in waveguides with periodically corrugated walls

Goryashko

Tarasov

Shostenko

2013

Waves in Random and Complex Media

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Starting from the rigorous excitation equation, the propagation of waves through a 2D waveguide with the periodically corrugated finite-length insert is examined in detail. The corrugation profile is chosen to obey the property that its amplitude is small as compared to the waveguide width, whereas the sharpness of the asperities is arbitrarily large. With the aid of the method of mode separation, which was developed earlier for inhomogeneous-in-bulk waveguide systems [Waves Random Media 10, 395 (2000)], the corrugated segment of the waveguide is shown to serve as the effective scattering barrier whose width is coincident with the length of the insert and the average height is controlled by the sharpness of boundary asperities. Due to this barrier, the mode spectrum of the waveguide can be substantially rarefied and adjusted so as to reduce the number of extended modes to the value arbitrarily less than that in the absence of corrugation (up to zero), without changing considerably the waveguide average width.

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“…특히 경계가 주기적으로 변하는 주름관 (Corrugated Duct)을 지나는 파동에 대해서 많은 연구가 이루어 졌다 [2][3][4][5][6][7][8][9][10][11][12] . 주름의 크기가 덕트 단면 크기에 비해 충분 히 작은 경우 섭동법 (Perturbation Method)을 이용한 연 구가 수행되었다 [2][3][4][5] .…”

Section: 서 론 격자형 형상이나 물성치가 주기적으로 변하는 구 조물내를 지나는 파동은 공학적으로 많은 응용분야unclassified

An Analysis of the Sound Stopband in Periodically Corrugated 2-D Ducts

Kim¹,

Kim²,

Kim³

et al. 2012

The Journal of the Acoustical Society of Korea

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ABSTRACT:In this paper, the occurrence of a stopband phenomenon when an acoustic wave propagates through periodically corrugated ducts is discussed using theoretical and BEM analyses. A 2-D duct with sinusoidally corrugated upper and lower walls is considered. When the magnitude of the sinusoidal corrugation is sufficiently small compared to the duct's height, the wave equation is solved with the multiple scaling perturbation method. Then stopbands for Bragg and non-Bragg resonances are computed from the condition where frequency becomes a complex number. A 2-D BEM analysis is performed to compute insertion loss of the duct, and stopbands are confirmed as predicted by analytical analysis.

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Non-Bragg reflections in a periodic waveguide

Cited by 33 publications

References 10 publications

Periodicity effects of axial waves in elastic compound rods

Periodicity effects of axial waves in elastic compound rods

The sharpness-induced mode stopping and spectrum rarefication in waveguides with periodically corrugated walls

An Analysis of the Sound Stopband in Periodically Corrugated 2-D Ducts

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