Parameter File Example

Below we describe the different sections of the “HelloWorld.in” input file we ran in the previous section:

Comments

The example input file begins with a comment header. Comments in Cello parameter files begin with # :

### Problem: Hello World
### Summary: Evolve high-pressure region shaped as an "E"
###    Date: 2011-10-27

Parameters are organized into “groups”, which may be nested. Below we look in turn at each group in the HelloWorld.in sample parameter file.

Domain Group

Domain {
   lower = [ 0.0, 0.0 ];
   upper = [ 1.0, 1.0 ];
}

Mesh Group

Mesh {
   root_size      = [160, 160];
   root_blocks    = [  1,   1 ];
}

Field Group

Field {

   ghost_depth  = 3;

   fields = [
      "density",
      "velocity_x",
      "velocity_y",
      "total_energy",
      "internal_energy"
    ];
}

Method Group

Method {

   list = [ "ppm" ];

   ppm {
      courant    = 0.8;
      diffusion  = true;
      flattening = 3;
      steepening = true;
   }
}

Physics Group

Physics {

   list = ["fluid_props"];

   fluid_props {
      eos {
         type = "ideal";
         gamma = 1.4;
      }
      dual_energy { type = "disabled"; }
   }
}

Initial Group

Initial {
    density       { value = [ 1.0,
    (0.35 < x && x < 0.40 && 0.25 < y && y < 0.70) ||
    (0.35 < x && x < 0.60 && 0.25 < y && y < 0.30) ||
    (0.35 < x && x < 0.60 && 0.45 < y && y < 0.50) ||
    (0.35 < x && x < 0.60 && 0.65 < y && y < 0.70),
                              0.125 ]; };
    total_energy  { value = [ 1.0  / (0.4 * 1.0) ,
    (0.35 < x && x < 0.40 && 0.25 < y && y < 0.75) ||
    (0.35 < x && x < 0.60 && 0.25 < y && y < 0.30) ||
    (0.35 < x && x < 0.60 && 0.45 < y && y < 0.55) ||
    (0.35 < x && x < 0.60 && 0.65 < y && y < 0.75),
                              0.14 / (0.4 * 0.1)]; };
    velocity_x    { value = [0.0]; };
    velocity_y    { value = [0.0]; }
}

Boundary Group

Boundary { type = "reflecting" }

Stopping Group

Stopping {
   cycle = 500;
}

Output Group

Output {

   file_groups = ["cycle_step"];

   cycle_step {
      field_list = ["density"];
      type     = "image";
      name     = ["E-%03d.png","cycle"];
      schedule = ["cycle","interval", 10];
      colormap = ["blue", "green", "yellow", "red"];
   }
}