# A Box with Reflecting Walls

## Front Tracking for the Euler Equations of Gas Dynamics

 In this example we consider a 2-D Riemann problem inside a square box (2x2 units) with reflecting walls. Initially the density is unity everywhere and the velocities zero. The pressure is equal 1.000 inside a square (0.5x0.5 units) in the center of the box and equal 10 elsewhere. The solution is computed using front tracking and dimensional splitting on a 400x400 grid. To reach time t=0.3 we use 1200 time steps. Click on the link(s) below to see snapshots of temperature, density, kinetic energy, and pressure. The images are quite spectacular! The simulation gets more polluted by numerical diffusion with time. Therefore we will not claim anything about validity of the phenomena depicted. START the slide show. Unfortunately the (color) axes are varying in the snapshots, so that equal values may be given different color in different pictures.

[ t=0.01 | t=0.02 | t=0.03 | t=0.04 | t=0.05 | t=0.06 | t=0.07 | t=0.08 | t=0.09 | t=0.10 ]
[ t=0.11 | t=0.12 | t=0.13 | t=0.14 | t=0.15 | t=0.16 | t=0.17 | t=0.18 | t=0.19 | t=0.20 ]
[ t=0.21 | t=0.22 | t=0.23 | t=0.24 | t=0.25 | t=0.26 | t=0.27 | t=0.28 | t=0.29 | t=0.30 ]

Knut-Andreas Lie <andreas@math.ntnu.no>