In this section we will see how to write a simulation file for the initial random vorticity example in the Gerris web site gallery. First of all, it is always a good idea to run simulations in their own directory. Type this at your shell prompt:
% mkdir vorticity % cd vorticityAs a starting point we will use the following simulation file: vorticity.gfs
1 2 GfsSimulation GfsBox GfsGEdge {} {
GfsTime { end = 0 }
}
GfsBox {}
1 1 right
1 1 top
This is a valid simulation file but it does not do much as you can see
by typing
% gerris2D vorticity.gfsIt is a good starting point however to explain the general structure of a simulation file.