DGFEM for Acoustic Wave Propagation

This repository implements a discontinuous Galerkin finite element method (DGFEM) applied to the linearized Euler equations and the acoustic perturbation equations. The solver is based on GMSH library and supports a wide range of features:

1D, 2D, 3D problems
4-th order Runge-Kutta
High order elements
Absorbing and reflecting boundaries
Support ‘json’ format configartion file
Multiple sources support: monopoles, dipoles, quadrupoles, user defined analytical formulation sources and external data (csv and sound ‘wave’ file supported)
Complex geometry and unstructured grid (only triangles (2D) and tetrahedrons (3D) elements are supported)
VTK post-processing (use Paraview)
User defined obervers position post-processing (text data time variables, Fast Fourier Transform, Pressure Power Spectral Density and sound ‘wave’ files)

Getting Started

Prerequisites

First, make sure the following libraries are installed. If you are running a linux distribution (ubuntu, debian, …), an installation script is provided.

Gmsh (v4.13.x)
Eigen (v3.x)
Lapack
Blas
OpenMP
~~Libtbb~~
VTK (v9.x)
FFTW

Installing

git clone https://github.com/skhelladi/DGFEM-CAA.git
cd DGFEM-CAA
sh build.sh

or use

git clone https://github.com/skhelladi/DGFEM-CAA.git
cd DGFEM-CAA
mkdir build && cd build
cmake ../ -DCMAKE_BUILD_TYPE=Release  -G "Unix Makefiles" -DGMSH_INCLUDE_DIRS="../gmsh-4.11.0-Linux64-sdk/include" -DGMSH_LIBRARIES="../gmsh-4.11.0-Linux64-sdk/lib/libgmsh.so" -DGMSH_EXECUTABLE="../gmsh-4.11.0-Linux64-sdk/bin/gmsh" -DEIGEN_INCLUDE_DIRS="/usr/include/eigen3"
make -j4

Running the tests

Once the sources sucessfully build, you can start using with the solver. It required two arguments: a mesh file created with Gmsh and a config file containing the solver options. Examples of mesh files and config files are given here.

cd bin
./dgalerkin myconfig.conf

cd bin
./dgalerkin myconfig.json

Minimal working example

2D propagation of an Gaussian initial condition over a square.

cd build/bin
./dgalerkin ../../doc/config/Square.conf 

cd build/bin
./dgalerkin ../../doc/config/Square.json 

or configure run_caa batch file with the right mesh and configurations files.

sh run_caa

Configuration file example

Text format file

meshFileName = doc/2d/square2.msh

# Initial, final time and time step(t>0)
timeStart=0
timeEnd=0.05
timeStep=0.00001

# Saving rate:
timeRate=0.001

# Element Type:
# ["Lagrange", "IsoParametric", ...]
elementType=Lagrange

# Time integration method:
# ["Euler1", "Euler2", "Runge-Kutta"...]
timeIntMethod=Runge-Kutta

# Boundary condition:
# /!\ The physical group name must match the Gmsh name (case sensitive)
# MyPhysicalName = Absorbing or Reflecting
Reflecting = Reflecting
Absorbing = Absorbing

# Number of thread
numThreads=12

# Mean Flow parameters
v0_x = -30
v0_y = 30
v0_z = 0
rho0 = 1.225
c0 = 100

# Source:
# name = fct,x,y,z,size,intensity,frequency,phase,duration
# - fct supported = [monopole, dipole, quadrupole, formula, file (csv, wav)]
# - if fct = formula => name = fct,"formula expr",x,y,z,size,duration (ex: formulat = 0.1 * sin(2 * pi * 50 * t))
# - if fct = file => name = fct,"filename",x,y,z,size
#	suported file formats are : csv, wav
# - (x,y,z) = source position
# - intensity = source intensity
# - frequency = source frequency
# NB: Extended source or Multiple sources are supported.
#     (source1 = ..., source2 = ...) indice must change.
source1 = formula, "0.1 * sin(2 * pi * 50 * t)", 0.0,0.0,0.0, 0.1, 0.1
source2 = monopole, 0.0,0.0,0.0, 0.1, 0.1,50,0,0.1
source3 = file,"data/data.csv", 0.0,0.0,0.0, 0.1
source4 = file,"data/data.wav", 0.0,0.0,0.0, 0.1
# source4 = udf, "-0.1 * sin(2 * pi * 50 * t)", -0.5,0.0,0.0, 0.1, 0.1

# Initial condition:
# name = gaussian,x,y,z, size, amplitude
# - fct supported = [gaussian]
# - (x,y,z) = position
# - amplitude = initial amplitude
# NB: Multiple CI are supported and recursively added.
#     (initial condition1 = ..., initial condition = ...)
# initialCondtition1 = gaussian, 0,0,0,1,1

# Observers position:
# name = x,y,z, size
# - (x,y,z) = position
# NB: Multiple observers are supported and recursively added.
#     (observer1 = ...; observer2 = ...)
observer1 = 2.11792,0.00340081,0.0,0.1
observer2 = -2.11792,0.00340081,0.0,0.1

Json format file

{
	"mesh": {
		"File": "doc/2d/square2.msh",
		"BC": {
			"number": 2,
			"boundary1": {
				"name": "Abs",
				"type": "Absorbing"
			},
			"boundary2": {
				"name": "Ref",
				"type": "Reflecting"
			}
		}
	},
	"solver": {
		"time": {
			"start": 0.0,
			"end": 0.05,
			"step": 5e-05,
			"rate": 0.001
		},
		"elementType": "Lagrange",
		"timeIntMethod": "Runge-Kutta",
		"numThreads": 12
	},
	"initialization": {
		"meanFlow": {
			"vx": 30.0,
			"vy": 0.0,
			"vz": 0.0,
			"rho": 1.225,
			"c": 100.0
		},
		"number": 2,
		"initialCondition1": {
			"type": "gaussian",
			"x": 0.2,
			"y": 0.0,
			"z": 0.0,
			"size": 1.0,
			"amplitude": 1.0
		},
		"initialCondition2": {
			"type": "gaussian",
			"x": -0.2,
			"y": 0.0,
			"z": 0.0,
			"size": 1.0,
			"amplitude": 1.0
		}
	},
	"observers": {
		"number": 2,
		"observer1": {
			"x": 2.11792,
			"y": 0.00340081,
			"z": 0.0,
			"size": 0.1
		},
		"observer2": {
			"x": -2.11792,
			"y": 0.00340081,
			"z": 0.0,
			"size": 0.1
		}
	},
	"sources": {
		"number": 3,
		"source1": {
			"type": "formula",
			"fct": "0.1 * sin(2 * pi * 50 * t)",
			"x": 0.0,
			"y": 0.0,
			"z": 0.0,
			"size": 0.1,
			"amplitude": 0.0,
			"frequency": 0.0,
			"phase": 0.0,
			"duration": 0.05
		},
		"source2": {
			"type": "file",
			"fct": "data/data2.wav",
			"x": 0.0,
			"y": 0.0,
			"z": 0.0,
			"size": 0.1,
			"amplitude": 0.0,
			"frequency": 0.0,
			"phase": 0.0,
			"duration": 0.05
		},
		"source3": {
			"type": "monopole",
			"fct": "",
			"x": 0.0,
			"y": 0.0,
			"z": 0.0,
			"size": 0.1,
			"amplitude": 0.1,
			"frequency": 50.0,
			"phase": 0.0,
			"duration": 0.05
		}
	}
}

License

This project is licensed under the GPL-3 license.

Author

Sofiane Khelladi

Forked from code developed by

Pierre-Olivier Vanberg
Martin Lacroix
Tom Servais

Link : https://github.com/pvanberg/DGFEM-Acoustic