[liugx212]

Hi all,
I got error message when I run buoyantFoam case without div(phi, U) term in UEqn as follows. Could anybody help me please?

Thanks a lot.

Starting time loop

Mean and max Courant Numbers = 0 0
Time = 0.025



--> FOAM FATAL IO ERROR : Unknown symmetric matrix solver BICCG

Valid symmetric matrix solvers are :

4
(
ICCG
GaussSeidel
DCG
AMG
)


file: /home/liu/OpenFOAM/liu-1.2/run/tutorials/buoyantFoam/hotRoom/system/fvSolution:: U at line 30.

From function lduMatrix::solver::New(const fvMesh&, Istream&)
in file matrices/lduMatrix/lduMatrixSolver.C at line 100.

FOAM exiting

[niklas]

First, this subject applies to almost EVERY discussion in this forum. So it does not describe
your problem very well, does it.
I feel like a broken record, but pleeease choose a topic that describes your problem.

second, you have posted the answer yourself,
it is in the error message.
It cannot be any clearer.

N

[vvqf]

Dear Guoxiang,

your "title" problem really puzzle us for a long time. I cant agree more with Niklas.
Do please choose a suitable title for your post. Do the fovor for both you and us.
The title I would suggest for your post might be "what solver for a symmetric matrix", or simplely "FOAM FATAL IO ERROR : Unknown symmetric matrix solver BICCG".

The message means you should not use BICCG solver but ICCG for your case setting. clearly described in your own message:
Valid symmetric matrix solvers are :
4
(
ICCG
GaussSeidel
DCG
AMG
)

in the FoamX:
go to fvSolution -> solvers to change it.

[vvqf]

fvSolution -> solvers -> U

usually you dont have such problem if you run the case with the solver default settings.
did you copy the case from one solver to another?
or
you are modifying the codes, implementing another equation inside the code?

[liugx212]

Thanks for your adice. I got it.

Guoxiang