A continuously cascaded conformal mapping for sound propagation over irregular terrain

2006 ◽  
Vol 119 (5) ◽  
pp. 3263-3263
Author(s):  
Santosh Parakkal ◽  
Kenneth E. Gilbert ◽  
Di Xiao
Keyword(s):  
Conformal Mapping ◽  
Sound Propagation ◽  
Irregular Terrain

A generalized polar coordinate method for sound propagation over large-scale irregular terrain

2010 ◽  
Vol 128 (5) ◽  
pp. 2573-2580 ◽  
Author(s):  
Santosh Parakkal ◽  
Kenneth E. Gilbert ◽  
Xiao Di ◽  
Henry E. Bass
Keyword(s):  
Large Scale ◽  
Sound Propagation ◽  
Coordinate Method ◽  
Irregular Terrain ◽  
Polar Coordinate

NUMERICAL SIMULATION OF LOW-FREQUENCY AEROACOUSTICS OVER IRREGULAR TERRAIN USING A FINITE ELEMENT DISCRETIZATION OF THE PARABOLIC EQUATION

2002 ◽  
Vol 10 (01) ◽  
pp. 97-111 ◽  
Author(s):  
NIKOLAOS A. KAMPANIS
Keyword(s):  
Boundary Condition ◽  
Finite Element ◽  
Sound Propagation ◽  
Nonlocal Boundary Condition ◽  
Nonlocal Boundary ◽  
Low Frequency ◽  
Initial Boundary ◽  
Computational Domain ◽  
Element Discretization ◽  
Irregular Terrain

Environmental noise raises serious concerns in modern industrial societies. As a result, the study of sound propagation in the atmosphere over irregular terrain is a subject of current interest in aeroacoustics. We use the standard parabolic approximation of the Helmholtz equation to simulate the far-field, low-frequency sound propagation in a refracting atmosphere, over terrains with mild range-varying topography. At an artificial upper boundary of the computational domain, described in range and height coordinates, a nonlocal boundary condition is used to model the effect of a homogeneous, semi-infinite atmosphere. We define a curvilinear coordinate system fitting the irregular topography. We discretize the transformed initial-boundary value problem with a finite element technique in height and a conservative Crank–Nicolson scheme for marching in range. The underlying transformation of coordinates allows the effective coupling with the nonlocal boundary condition. The resulting discretization method is accurate and efficient for the numerical prediction of noise levels in the atmosphere.

scholarly journals Atmospheric Sound Propagation Over Large-Scale Irregular Terrain

2014 ◽  
Vol 61 (2) ◽  
pp. 369-397 ◽  
Author(s):  
Martin Almquist ◽  
Ilkka Karasalo ◽  
Ken Mattsson
Keyword(s):  
Large Scale ◽  
Sound Propagation ◽  
Irregular Terrain
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