Investigation of Wave Field Stability for Sound Propagation in the Structured Ocean: A Dynamical Systems Approach to Wave Propagation in Random Media

2003 ◽  
Author(s):  
Michael A. Wolfson
Keyword(s):  
Wave Propagation ◽  
Dynamical Systems ◽  
Wave Field ◽  
Random Media ◽  
Sound Propagation ◽  
Systems Approach

Conservation of energy in random media, with application to the theory of sound absorption by an inhomogeneous flexible plate

1973 ◽  
Vol 331 (1587) ◽  
pp. 479-496 ◽  
Keyword(s):  
Wave Propagation ◽  
Wave Field ◽  
Random Media ◽  
Mass Density ◽  
Second Law Of Thermodynamics ◽  
Coupled Systems ◽  
Flexible Plate ◽  
Random Component ◽  
Power Flux ◽  
Conservation Of Energy

This paper discusses the linear theory of wave propagation through conservative random media. By means of a simple illustrative example taken from acoustics it is verified that, at least uniformly to second order in an expansion parameter associated with the random fluctuations, the net flow of energy is from the mean, or coherent, wave field to the random component of the wave field (in accordance with the second law of thermodynamics). A general formula is derived for the distribution of the random modes of the system responsible for the power flux into the random field. These are demonstrated unambiguously (without recourse to the use of far field asymptotics) to be precisely those propagating modes which satisfy the homogeneous, non-random dispersion relation. The extension of the theory to a wider class of wave propagation problems is then outlined using an approach involving a Lagrangian density of wide generality. Finally the discussion is extended further to cover the case of coupled systems of wave-bearing media. An important analytical feature of such cases is the occurrence of ‘branch-cut’ integrals in the power flux formula. The situation is illustrated by an investigation of the power extracted from a plane sound wave incident on a flexible plate whose mass density is a random function of position. The division of the scattered power between the acoustic and plate bending modes is obtained, and comparison made with a heuristic argument leading to the same result.

scholarly journals Anomalous Anderson localization behavior in gain-loss balanced non-Hermitian systems

Nanophotonics ◽  
2020 ◽  
Vol 10 (1) ◽  
pp. 443-452
Author(s):  
Tianshu Jiang ◽  
Anan Fang ◽  
Zhao-Qing Zhang ◽  
Che Ting Chan
Keyword(s):  
Wave Propagation ◽  
Electromagnetic Waves ◽  
Anderson Localization ◽  
Random Media ◽  
Normal Incidence ◽  
Disordered Media ◽  
One Dimensional ◽  
Gain Loss ◽  
The Waves ◽  
Localization Behavior

AbstractIt has been shown recently that the backscattering of wave propagation in one-dimensional disordered media can be entirely suppressed for normal incidence by adding sample-specific gain and loss components to the medium. Here, we study the Anderson localization behaviors of electromagnetic waves in such gain-loss balanced random non-Hermitian systems when the waves are obliquely incident on the random media. We also study the case of normal incidence when the sample-specific gain-loss profile is slightly altered so that the Anderson localization occurs. Our results show that the Anderson localization in the non-Hermitian system behaves differently from random Hermitian systems in which the backscattering is suppressed.

Streamer saturation: a dynamical systems approach

2006 ◽  
Vol 351 (6) ◽  
pp. 417-423 ◽  
Author(s):  
F. Jenko
Keyword(s):  
Dynamical Systems ◽  
Systems Approach

Universality of Wave Propagation in Random Media

1990 ◽  
Vol 11 (8) ◽  
pp. 733-738 ◽  
Author(s):  
A. Z Genack
Keyword(s):  
Wave Propagation ◽  
Random Media
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