Ahmed,
The code supports supports the creation of 3D models (i.e., 3D cylinders, planes, etc. are all supported). However, the public version of the code can only solve a solution along a 2D “slice” of the geometry at a single axial location along the z-axis.
You can take a look at a full 3D model in our “c5g7-3d-rodded-B.py” example input. As you can see here, a user can specify where to “slice” the geometry along the z-axis with the “TrackGenerator.setZCoord(…)” method. in this case, the solver will look at the geometry at z=-20.0 and treat it as infinitely long along the z-axis.
New releases of OpenMOC will support fully 3D solutions to the neutron transport equation later this year.
Best,
Will