Simulation of sound waves using the Lattice Boltzmann Method for fluid flow: Benchmark cases for outdoor sound propagation
article
Propagation of sound waves in air can be considered as a special case of fluid dynamics.
Consequently, the lattice Boltzmann method (LBM) for fluid flow can be used for simulating
sound propagation. In this article application of the LBM to sound propagation is illustrated
for various cases: free-field propagation, propagation over porous and non-porous ground,
propagation over a noise barrier, and propagation in an atmosphere with wind. LBM results
are compared with solutions of the equations of acoustics. It is found that the LBM works
well for sound waves, but dissipation of sound waves with the LBM is generally much larger
than real dissipation of sound waves in air. To circumvent this problem it is proposed here to
use the LBM for assessing the excess sound level, i.e. the difference between the sound
level and the free-field sound level. The effect of dissipation on the excess sound level is
much smaller than the effect on the sound level, so the LBM can be used to estimate the
excess sound level for a non-dissipative atmosphere, which is a useful quantity in atmospheric
acoustics. To reduce dissipation in an LBM simulation two approaches are considered:
i) reduction of the kinematic viscosity and ii) reduction of the lattice spacing.
Consequently, the lattice Boltzmann method (LBM) for fluid flow can be used for simulating
sound propagation. In this article application of the LBM to sound propagation is illustrated
for various cases: free-field propagation, propagation over porous and non-porous ground,
propagation over a noise barrier, and propagation in an atmosphere with wind. LBM results
are compared with solutions of the equations of acoustics. It is found that the LBM works
well for sound waves, but dissipation of sound waves with the LBM is generally much larger
than real dissipation of sound waves in air. To circumvent this problem it is proposed here to
use the LBM for assessing the excess sound level, i.e. the difference between the sound
level and the free-field sound level. The effect of dissipation on the excess sound level is
much smaller than the effect on the sound level, so the LBM can be used to estimate the
excess sound level for a non-dissipative atmosphere, which is a useful quantity in atmospheric
acoustics. To reduce dissipation in an LBM simulation two approaches are considered:
i) reduction of the kinematic viscosity and ii) reduction of the lattice spacing.
TNO Identifier
531292
Source
PLOS One, pp. 1-19.
Pages
1-19