Wave protection comparison 10: triangles pointing right vs triangles pointing left
Channel: Nils Berglund
Date: 02/12/2021

This simulation compares two energy barriers composed of regularly arranged equilateral triangles, pointing either towards, or away from the incoming wave. It demonstrates that the second design is more effective at reflecting the wave, as it lets only about half as much energy pass the structure. 
The colors indicate the wave's energy, according to the color bar on the right. The numbers at the top, bottom and corners indicate, for each panel, the total energy in the area filled with obstacles, at its left and at its right. 

Render time: 20 minutes
Color scheme: Inferno by Nathaniel J. Smith and Stefan van der Walt
https://github.com/BIDS/colormap

Music: "Irie" by Quincas Moreira@QuincasMoreira

See also https://images.math.cnrs.fr/Des-ondes-dans-mon-billard-partie-I.html for more explanations (in French) on  a few previous simulations of wave equations. 

The simulation solves the wave equation by discretization. The algorithm is adapted from the paper https://hplgit.github.io/fdm-book/doc/pub/wave/pdf/wave-4print.pdf 
C code: https://github.com/nilsberglund-orleans/YouTube-simulations
https://www.idpoisson.fr/berglund/software.html 
Many thanks to my colleague Marco Mancini for helping me to accelerate my code!