HYPRE with multiple variables

[Nicolas Bathfield]

Barry,

Boomeramg used to diverge right away for all Reynolds numbers and size of
grids...After I used MatSetBlockSize, I could see an improvement in some
cases probably when the coupling between my variables was not that strong
(just a guess).
>From papers written by Rob Falgout I read, I could see that without
HYPRE_BOOMERAMGSetNodal, boomermang deals with the variables
independently, like a segregated solver.

Thanks a lot for your help.

Best regards,

Nicolas


>
>   Nicolas,
>
> On Wed, 25 Apr 2007, Nicolas Bathfield wrote:
>
>> Dear Barry,
>>
>> Using MatSetBlockSize(A,5) improved my results greatly. Boomemramg is
>> now
>> solving the system of equations.
>
>    Good
>
>> Still, the equations I solve are coupled, and my discretization scheme
>> is
>> meant for a non-segregated solver. As a consequence (I believe),
>> boomeramg
>> still diverges.
>
>   How can "Boomeramg be now solving the system of equations" but also
> diverge? I am so confused.
>
>>  I would therefore like to use the nodal relaxation in
>> boomeramg (the hypre command is HYPRE_BOOMERAMGSetNodal) in order to
>> couple%