wavextrema

Note: This is not an officially supported Google product

Introduction

This project is an implementation of acoustic simulation. currently, it supports the boundary element method in 2D and 3D for solving the Helmholtz equation.

• Solves 2D and 3D BEM systems with Dirichlet, Neumann, or mixed boundary conditions.
• Future plans
  • Optimizing splines to optimize structures for acoustic properties.
  • Lumped models for modeling e.g. electromechanical systems like Thiele-Small speakers and crossovers.
  • FEM methods for elastic deformation coupling with acoustics simulation.

This was primarily written to handle horns for hobby loudspeakers. The math used in this software is discussed in detail in

• Kirkup, Stephen Martin. The boundary element method in acoustics. Integrated sound software, 2007.

Beside the Berton-Miller method used in Kirkup, we also implement the more modern, faster, and simpler Dual Surface method as in

• Mohsen, A., and M. Hesham. "An efficient method for solving the nonuniqueness problem in acoustic scattering." Communications in numerical methods in engineering 22.11 (2006): 1067-1076.

Getting started

Run some examples. All examples are listed if you run bem_examples.py with no arguments.

pip3 install --upgrade quadpy scipy gmshparser matplotlib
python3 wavextrema/bem_examples.py example   # Get list of options
python3 wavextrema/bem_examples.py example1  # Run basic 1d
python3 wavextrema/bem_examples.py example2  # Run basic 2d

Using a mesh

If you make a mesh using gmsh and make a physical group "emit", you can see how normal emission will effect directional frequency response.

python3 wavextrema/run_directivity.py meshes/example_waveguide.msh

produces

Apache header:

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