https://github.com/Universite-Gustave-Eiffel/WAPE
https://github.com/Universite-Gustave-Eiffel/WAPE
Last synced: about 2 months ago
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- Host: GitHub
- URL: https://github.com/Universite-Gustave-Eiffel/WAPE
- Owner: Universite-Gustave-Eiffel
- License: eupl-1.2
- Created: 2022-12-15T10:34:34.000Z (almost 3 years ago)
- Default Branch: main
- Last Pushed: 2024-07-17T13:39:13.000Z (over 1 year ago)
- Last Synced: 2024-07-17T16:48:37.477Z (over 1 year ago)
- Language: MATLAB
- Size: 1.42 MB
- Stars: 3
- Watchers: 1
- Forks: 0
- Open Issues: 0
-
Metadata Files:
- Readme: README.md
Awesome Lists containing this project
- awesome-acoustic - WAPE
README
# Wide Angle Parabolic Equation model with arbitrary Mach number
The WAPE model proposed here is an implementation of the work of [Ostashev et al 2020]. The WAPE is developed using a Padé(1,1) series expansion. A Crank-Nicholson algorithm is used to reduce the equation into a matrix system. Then, the 2D acoustic pressure field is calculated using a second-order centered finite difference scheme on velocity potential.
This code is intended to be shared with the research community.
## Installation
This WAPE model is designed to run with [Matlab](https://www.mathworks.com/products/matlab.html), without any additonal toolbox.
## Run a calculation
To run a calculation you need to open "initialisation_WAPE.m", set parameters values, and run the script. It is indicated which parameter can be modified and which can not.
The input parameters are:
```Matlab
%% Source parameters
freq = 250; % source frequency (Hz)
hS = 35; % source height (m)
%% Medium properties
T = 10; % atmospheric temperature at the surface (°C)
Tlog = 0.2; % temperature coefficient for the vertical gradient
shear_exp = 0.15; % wind shear exponents (scalar) for power law wind profil
v_ref = 5; % wind speed (m/s) measured at z_ref height, for power-law wind profile
z_ref = 80; % reference height for wind speed v_ref
theta = 0; % propagation angle with respect to the source (0° : downwind, 180° : upwind)
f_turb_ind = true; % logical 'true' or 'false' to account for turbulence or not
gamT = 0; % turbulence strength
%% 2D Spatial domain (x,z)
dim_x = 3000; % horizontal dimension x of the domain (m)
dim_z = 300; % vertical dimension z of the domain (m)
haut_a = 0.8; % where the absorbing layer starts at the top of the domain, according to z axis (0.8 ==> start at 80% of z axis)
coeff_a = 10; % damping rate
discrx = 10; % discretization x = lambda/discrx
discrz = 10; % discretization z = lambda/discrz
z_r = 1.5; % receiver height for plotting (m)
%% Ground properties
hv = 0; % vegetation height (m), it affects the shape of atmospheric profils
z0 = 0.13*hv + 0.00001; % atmospheric roughness length (m), can't be null
d = 0.66*hv; % displacement height of flux profiles (m), it's directly linked to vegetation height
lc = 0 ; % correlation length (m) (ground roughness parameter), if 0 : no ground rugositiy, [0.05-1]
sigmah = 0; % standard deviation of roughness height (m) (ground roughness parameter), [0.01-0.05]
sigma = 10000000; % airflow resistivity of the ground (kN.s.m-4)
h = 0; % thickness of ground surface layer (m), if h = 0 no layer
```
## Post-processing
When the simulation has completed there will be 'DeltaL.mat' and 'normalized_SPL.mat' files which correspond respectively to attenuation to free field (dB), and sound pressure level field (dB) which is normalized by the maximum amplitude. You can post-process these signals to your liking. Here is an exemple of output:
## Warning
Instabilities can occur with PE simulations if:
- the spatial steps are too large,
- the absorbent layer at the top of the domain is not thick enough.
Calculation time can be really long and take a lot of memory if:
- the spatial steps are too small,
- the domain is too big,
- the frequency is too high.
## License
This code is released under the EUPL license.
## Credits
The development of this code took part into the french [PIBE project](https://www.anr-pibe.com/) (contract ANR-18-CE04-0011).
## Citing this work
If this WAPE script contributes to an academic publication, please cite it as:
@misc{kayser_wide_2023,
title = {Wide-angle parabolic equation model},
url = {https://github.com/bkayser13/WAPE/},
author = {Kayser, Bill},
year = {2023},
note = {https://github.com/bkayser13/WAPE/},
}
## Some background references
This code largely implements algorithms that have already been published. A non-exhaustive list is proposed below.
Tappert, F. D. (1977). The parabolic approximation method. Wave propagation and underwater acoustics, 224-287.
Gilbert, K. E., & White, M. J. (1989). Application of the parabolic equation to sound propagation in a refracting atmosphere. The Journal of the Acoustical Society of America, 85(2), 630-637.
West, M., Gilbert, K., & Sack, R. A. (1992). A tutorial on the parabolic equation (PE) model used for long range sound propagation in the atmosphere. Applied Acoustics, 37(1), 31-49.
Collins, M. D. (1993). A split‐step Padé solution for the parabolic equation method. The Journal of the Acoustical Society of America, 93(4), 1736-1742.
Ostashev, V. E., Juvé, D., & Blanc-Benon, P. (1997). Derivation of a wide-angle parabolic equation for sound waves in inhomogeneous moving media. Acta Acustica united with Acustica, 83(3), 455-460.
Dallois, L., Blanc-Benon, P., & Juvé, D. (2001). A wide-angle parabolic equation for acoustic waves in inhomogeneous moving media: Applications to atmospheric sound propagation. Journal of Computational Acoustics, 9(02), 477-494.
Lihoreau, B., Gauvreau, B., Bérengier, M., Blanc-Benon, P., & Calmet, I. (2006). Outdoor sound propagation modeling in realistic environments: Application of coupled parabolic and atmospheric models. The Journal of the Acoustical Society of America, 120(1), 110-119.
Cheinet, S. (2012). A numerical approach to sound levels in near-surface refractive shadows. The Journal of the Acoustical Society of America, 131(3), 1946-1958.
Kayser, B., Gauvreau, B., & Ecotière, D. (2019). Sensitivity analysis of a parabolic equation model to ground impedance and surface roughness for wind turbine noise. The Journal of the Acoustical Society of America, 146(5), 3222-3231.
Ostashev, V. E., Muhlestein, M. B., & Wilson, D. K. (2019). Extra-wide-angle parabolic equations in motionless and moving media. The Journal of the Acoustical Society of America, 145(2), 1031-1047.
Ostashev, V. E., Wilson, D. K., & Muhlestein, M. B. (2020). Wave and extra-wide-angle parabolic equations for sound propagation in a moving atmosphere. The Journal of the Acoustical Society of America, 147(6), 3969-3984.