Simple Meshes¶

You can generate simple structured meshes from the command-line using the fame-simple command. This generates either a 2D or a 3D mesh, aligned with a straight, uniform magnetic field. By default, the field is parallel to the x1 direction, but you can configure it to be offset by some angle.

Your mesh is made up of “layers” in the field-aligned direction. Elements within a layer are all conformal with each other and all follow the direction of the magnetic field. There will be a nonconformal interface with adjacent layers. Each layer is identical, apart from its position on the x1-axis. Each layer may be further subdivided along the x1 axis but, as stated above, these elements will be conformal.

2D Meshes¶

You can try generating a simple 10 by 10 2D mesh on the domain \(x_1 \in [0, 1], x_2 \in [0, 1]\), aligned to a field shifted by 1 degree from the x1-direction, by running:

fame-simple 2d --nx1 4 --nx2 4 --angle -2 simple_mesh.xml

This will save the mesh to simple_mesh.xml in the Nektar++ format. When visualising that mesh we get the following.

By default, the number of layers in the x1-direction is the same as the number of elements. This can be adjusted by using the --layers option. For example, if you want only two nonconformal layers you can specify this using the --layers option:

fame-simple 2d --nx1 4 --nx2 4 --angle -2 --layers 1 simple_mesh.xml

That mesh will look like the image below.

Run fame-simple 2d --help to find out about additional options for configuring your mesh.

3D Meshes¶

The process of generating a 3D mesh is very similar. For example, to produce a mesh with the following properties - 10 by 20 by 8 elements - domain \(x_1 \in [0, 100], x_2 \in [0, 200], x_3 \in [0, 80]\) - aligned to a field rotate by 3 degrees away from the x1-axis and towards the x2-axis - with 5 nonconformal layers

you should run:

fame-simple 3d --nx1 10 --nx2 20 --nx3 8 --x1-extent 0 100 \
            --x2-extent 0 200 --x3-extent 0 80 --angle1 3 \
            --layers 5 3d_mesh.xml

This would produce the following mesh.

Again, you can get more information about the options available by running fame-simple 3d --help.