EffectiveWaves

A Julia package for calculating, processing and plotting waves travelling in heterogeneous materials. The focus is on ensemble averaged waves.

Documentation	Build Status

At present, the packages calculates effective wavenumbers, wave transimission and wave reflection from random particulate materials in two-dimensions, see arXiv preprint for details on the mathematics, or these notes for the formulas.

Installation

Type into Julia:

using Pkg
Pkg.clone("https://github.com/arturgower/EffectiveWaves.jl.git")

using EffectiveWaves

Documentation

• STABLE — documentation of the most recently tagged version.
• DEVEL — documentation of the in-development version.

Simple example

Effective wavenumbers for two species randomly (uniformly) distributed in Glycerol.

#where: ρ = density, r = radius, c = wavespeed, and volfrac = volume fraction

const WaterDistilled= Medium(ρ=0.998*1000, c = 1496.0)
const Glycerol      = Medium(ρ=1.26*1000,  c = 1904.0)

species = [
    Specie(ρ=WaterDistilled.ρ,r=30.e-6, c=WaterDistilled.c, volfrac=0.1),
    Specie(ρ=Inf, r=100.0e-6, c=2.0, volfrac=0.2)
]
# background medium
background = Glycerol

Calculate effective wavenumbers:

# angular frequencies
ωs = LinRange(0.01,1.0,60)*30.0e6
wavenumbers = wavenumber_low_volfrac(ωs, background, species)

speeds = ωs./real(wavenumbers)
attenuations = imag(wavenumbers)

For a list of possible materials go to src/materials.jl.

More examples

For more examples and details go to docs/src/examples/.

Acknowledgements and contributing

This library was originally written by Artur L Gower. Contributions are very welcome.

References

[1] Gower AL, Smith MJ, Parnell WJ, Abrahams ID. Reflection from a multi-species material and its transmitted effective wavenumber. Proc. R. Soc. A. 2018 Apr 1;474(2212):20170864.

[2] Gower, Artur L., William J. Parnell, and I. David Abrahams. "Multiple waves propagate in random particulate materials." SIAM Journal on Applied Mathematics 79.6 (2019): 2569-2592.

[3] Gower, Artur L., I. David Abrahams, and William J. Parnell. "A proof that multiple waves propagate in ensemble-averaged particulate materials." Proceedings of the Royal Society A 475.2229 (2019): 20190344.