Search results for " Perturbation method."

showing 2 items of 2 documents

Wave propagation in anisotropic turbulent superfluids

2013

In this work, a hydrodynamical model of Superfluid Turbulence previously formulated is applied to study how the presence of a non-isotropic turbulent vortex tangle modifies the propagation of waves. Two cases are considered: wave front parallel and orthogonal to the heat flux. Using a perturbation method, the first-order corrections due to the presence of the vortex tangle to the speeds and to the amplitudes of the first and second sound are determined. It is seen that the presence of the quantized vortices couples first and second sound, and the attenuation of second sound is proportional to the line density L if the wave propagates orthogonal to the heat flux, while it is proportional to …

WavefrontPhysicsAnisotropic superfluid turbulence Quantized vortices Wave propagation Second sound Perturbation method.TurbulenceWave propagationApplied MathematicsGeneral MathematicsAttenuationGeneral Physics and AstronomyMechanicsSuperfluidityAmplitudeClassical mechanicsHeat fluxSecond soundSettore MAT/07 - Fisica Matematica
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Analytical results for 2-D non-rectilinear waveguides based on a Green's function

2008

We consider the problem of wave propagation for a 2-D rectilinear optical waveguide which presents some perturbation. We construct a mathematical framework to study such a problem and prove the existence of a solution for the case of small imperfections. Our results are based on the knowledge of a Green's function for the rectilinear case.

wave propagation • optical waveguides • Green's function • perturbation methods
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