[Mr. Yoyo]

Hi,

I am using simpleFoam with the GAMG solver to solve for the pressure equation. I am using a smoothSolver to solve for U, k and omega. My case is a 3D wing unstructured tetrahedral mesh with ~2 miillion nodes.

What I would like to know is where I can see the number of grid levels generated by the GAMG solver. I understand that the GAMG is performing a V-cycle multi grid method and all the user must set is the "nCellsInCoarsestLevel" option, but I want to be able to set "nLevels" if such a parameter exists. At least, I want to know what nLevels is when the number fo cells on the coarsest mesh is set.

Any insight is much appreciated.

[mszeto715]

Turn on the GAMG DebugSwitches and your log file should include exactly how many levels are in your V cycle and how many cells are in each processor.

In system/controlDict, you can set up a DebugSwitches section with the following:
GAMG 1;
GAMGAgglomeration 1;
GAMGInterface 1;
GAMGInterfaceField 1;


Most likely, your GAMG is coarsening by one half for each level, so you can also just divide by 2 successively until you reach the level that has at least nCellsInCoarsestLevel.

You can see all the DebugSwitch options in the etc/controlDict file.


-Mimi