I use OpenFOAM for CFD simulations. A very popular preconditioner is GAMG which needs a low number of iterations per a time step in SIMPLE or PISO solvers that are used to simulate the fluid flow.
I would like to understand how GAMG prepares the internal structures.
Does it create the internal data structures used in GAMG only once in a single iteration on the basis of the geometry and then the entries in these data structures are only updated?
Does it create the interal data structures multiple times in a single iteration? I read the documentation here but it does not have the answer.
Thanks for your answer.