Adding a problem

The easiest way to add a problem is to copy an existing problem setup in the solver you wish to use (in its problems/ sub-directory). Three different files will need to be copied (created):

• problem.py: this is the main initialization routine. The function init_data() is called at runtime by the Simulation object’s initialize() method. Two arguments are passed in, the simulation’s CellCenterData2d object and the RuntimeParameters object. The job of init_data() is to fill all of the variables defined in the CellCenterData2d object.

• _problem.defaults: this contains the runtime parameters and their defaults for your problem. They should be placed in a block with the heading [problem] (where problem is your problem’s name). Anything listed here will be available through the RuntimeParameters object at runtime.

• inputs.problem: this is the inputs file that is used at runtime to set the parameters for your problem. Any of the general parameters (like the grid size, boundary conditions, etc.) as well as the problem-specific parameters can be set here. Once the problem is defined, you need to add the problem name to the __all__ list in the __init__.py file in the problems/ sub-directory. This lets python know about the problem.