Equations for finite-difference, time-domain simulation of sound propagation in moving inhomogeneous media and numerical implementation

Abstract

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Time-Domain Simulations of Outdoor Sound Propagation with Suitable Impedance Boundary Conditions

“…The relation r 0 c 2 v rP 0 v is then obtained. In the case of a moving inhomogeneous atmosphere, rP 0 is in the order jvj 2 =c 2 [17]. Thus, the term r 0 c 2 v, which is proportional to rP 0 , should be ignored in Eq.…”

“…(4). Moreover, following Ostashev et al [17], it can be shown that r V 0 jvj 3 =c 2 L, where L is the length scale of variations in the density 0 . As a result, the term pr V 0 is also neglected in Eq.…”

Simulating acoustic scattering from atmospheric temperature fluctuations using a k-space method

“…9 In contrast, numerical algorithms such at Finite-Difference-Time-Domain (FDTD) can directly model the scattering of these transient acoustic pulses by a specific temperature and velocity distribution. [10][11][12] Given however that SODARs generally operate in the frequency range 1000-5000 Hz and generally have a range of 100 m upward, FDTD simulation of the entire scattering volume in three dimensions is unfortunately not feasible with currently available computing power.…”

Meteorological effects on the noise reducing performance of a low parallel wall structure

“…Discriminating features of the numerical techniques are the possibility to model wind and/or turbulence, whether calculations were performed in two dimensions or in 3D, and whether the effective sound speed approach [11][15] was used or the (full) Linearised Euler Equations (LEE) [16][17] [18] were solved when modelling wind effects. The frequency range considered contains the 1/3 octave bands between 50 Hz to 2500 Hz.…”