Outdoor Sound Propagation in Inhomogeneous Atmosphere via Precomputation

2019 ◽  
Author(s):  
Jin Liu ◽  
Shiguang Liu
Keyword(s):  
Sound Propagation ◽  
Inhomogeneous Atmosphere

A FINITE ELEMENT METHOD FOR THE PARABOLIC EQUATION IN AEROACOUSTICS COUPLED WITH A NONLOCAL BOUNDARY CONDITION FOR AN INHOMOGENEOUS ATMOSPHERE

2005 ◽  
Vol 13 (04) ◽  
pp. 569-584 ◽  
Author(s):  
NIKOLAOS A. KAMPANIS
Keyword(s):  
Finite Element Method ◽  
Boundary Condition ◽  
Finite Element ◽  
Parabolic Equation ◽  
Sound Propagation ◽  
Nonlocal Boundary Condition ◽  
Nonlocal Boundary ◽  
Computational Domain ◽  
Inhomogeneous Atmosphere ◽  
Element Method

The standard parabolic equation is used to simulate the far-field, low-frequency sound propagation over ground with mild range-varying topography. The atmosphere has a lower layer with a general, variable index of refraction. An unbounded upper layer with a squared refractive index varying linearly with height is considered and modeled by the nonlocal boundary condition of Dawson, Brooke and Thomson.1 A finite element/transformation of coordinates method is used to transform the initial-boundary value problem to one with a rectangular computational domain and then discretize it. The solution is marched in range by the Crank–Nicolson scheme. A discrete form of the nonlocal boundary condition, which is left unaffected by the transformation of coordinates, is employed in the finite element method. The fidelity of the overall method is shown in the numerical simulations performed for various cases of sound propagation in an inhomogeneous atmosphere over a ground with irregular topography.

Sound as a transverse wave

2017 ◽  
Vol 13 (1) ◽  
pp. 4522-4534
Author(s):  
Armando Tomás Canero
Keyword(s):  
Quantum Mechanics ◽  
Gravitational Waves ◽  
Longitudinal Wave ◽  
Transverse Wave ◽  
Sound Propagation ◽  
Correspondence Principle ◽  
Classical Mechanics ◽  
Wave Model ◽  
Scientific Experiments

This paper presents sound propagation based on a transverse wave model which does not collide with the interpretation of physical events based on the longitudinal wave model, but responds to the correspondence principle and allows interpreting a significant number of scientific experiments that do not follow the longitudinal wave model. Among the problems that are solved are: the interpretation of the location of nodes and antinodes in a Kundt tube of classical mechanics, the traslation of phonons in the vacuum interparticle of quantum mechanics and gravitational waves in relativistic mechanics.

Time-domain calculation of sound propagation in lined ducts with sheared flows

AIAA Journal ◽  
2000 ◽  
Vol 38 ◽  
pp. 768-773 ◽  
Author(s):  
Yusuf Ozyoruk ◽  
Lyle N. Long
Keyword(s):  
Time Domain ◽  
Sound Propagation ◽  
Sheared Flows ◽  
Lined Ducts

A verified model of laser-generated sound propagation

1989 ◽  
Author(s):  
EDMOND LO ◽  
R. FERGUSON ◽  
MICHAEL FRISH ◽  
PETERE. NEBOLSINE
Keyword(s):  
Sound Propagation
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