[dinonettis]

hi foamers,

I'm struggling with turbfoam to analyze a rae2822 profile at Ma=0.1. Unfortunately, after hundreds of trials, I cannot understand which is the reason of the following behaviour in the solving phase:

-----------------------------------
Time = 1e-07

Courant Number mean: 4.12403e-05 max: 0.101726
DILUPBiCG: Solving for Ux, Initial residual = 6.40149e-07, Final residual = 6.40149e-07, No Iterations 0
DILUPBiCG: Solving for Uy, Initial residual = 8.01029e-07, Final residual = 8.01029e-07, No Iterations 0
DICPCG: Solving for p, Initial residual = 1, Final residual = 8.84861e-07, No Iterations 287
time step continuity errors : sum local = 5.46271e-17, global = -1.38422e-19, cumulative = -1.38422e-19
DICPCG: Solving for p, Initial residual = 0.973936, Final residual = 9.48497e-07, No Iterations 173
time step continuity errors : sum local = 2.20513e-15, global = -2.89127e-17, cumulative = -2.90511e-17
ExecutionTime = 1.96 s ClockTime = 2 s

Time = 2e-07

Courant Number mean: 3.21842e-05 max: 0.0600543
DILUPBiCG: Solving for Ux, Initial residual = 6.38914e-06, Final residual = 4.59744e-10, No Iterations 1
DILUPBiCG: Solving for Uy, Initial residual = 6.00179e-05, Final residual = 1.46503e-08, No Iterations 1
DICPCG: Solving for p, Initial residual = 0.721604, Final residual = 9.80245e-07, No Iterations 227
time step continuity errors : sum local = 8.18584e-15, global = -2.30115e-16, cumulative = -2.59166e-16
DICPCG: Solving for p, Initial residual = 0.985775, Final residual = 9.32614e-07, No Iterations 17
time step continuity errors : sum local = 5.72685e-14, global = 1.72613e-15, cumulative = 1.46696e-15
ExecutionTime = 2.56 s ClockTime = 3 s

Time = 3e-07

Courant Number mean: 3.05743e-05 max: 0.0594463
DILUPBiCG: Solving for Ux, Initial residual = 1.51317e-06, Final residual = 1.98958e-10, No Iterations 1
DILUPBiCG: Solving for Uy, Initial residual = 1.99655e-06, Final residual = 7.1546e-10, No Iterations 1
DICPCG: Solving for p, Initial residual = 0.998324, Final residual = 9.50503e-07, No Iterations 19
time step continuity errors : sum local = 1.0566e-12, global = 3.36326e-15, cumulative = 4.83022e-15
DICPCG: Solving for p, Initial residual = 0.994451, Final residual = 8.13027e-07, No Iterations 35
time step continuity errors : sum local = 1.50461e-11, global = 5.77993e-15, cumulative = 1.06102e-14
ExecutionTime = 2.8 s ClockTime = 3 s

Time = 4e-07

Courant Number mean: 0.000238724 max: 7.8394
DILUPBiCG: Solving for Ux, Initial residual = 2.80703e-06, Final residual = 7.6764e-07, No Iterations 1
DILUPBiCG: Solving for Uy, Initial residual = 4.02692e-06, Final residual = 9.52703e-08, No Iterations 2
DICPCG: Solving for p, Initial residual = 0.999406, Final residual = 9.43949e-07, No Iterations 66
time step continuity errors : sum local = 2.91744e-10, global = 1.50479e-11, cumulative = 1.50585e-11
DICPCG: Solving for p, Initial residual = 0.997245, Final residual = 8.13404e-07, No Iterations 15
time step continuity errors : sum local = 4.73266e-09, global = 1.36223e-11, cumulative = 2.86809e-11
ExecutionTime = 3.1 s ClockTime = 3 s

-
-
-

Time = 1.5e-06

Courant Number mean: 1.14736e+34 max: 5.85457e+39
DILUPBiCG: Solving for Ux, Initial residual = 0.999881, Final residual = 6.64112e-07, No Iterations 2
DILUPBiCG: Solving for Uy, Initial residual = 0.99987, Final residual = 1.72012e-09, No Iterations 2
DICPCG: Solving for p, Initial residual = 1, Final residual = 2.10565e-10, No Iterations 4
time step continuity errors : sum local = 3.81358e+64, global = 7.99287e+53, cumulative = 7.99287e+53
DICPCG: Solving for p, Initial residual = 1, Final residual = 1.30033e-07, No Iterations 3
time step continuity errors : sum local = 8.71925e+69, global = 1.12494e+55, cumulative = 1.20487e+55
ExecutionTime = 12.51 s ClockTime = 13 s

Time = 1.6e-06

Courant Number mean: 2.62689e+75 max: 1.15657e+82
DILUPBiCG: Solving for Ux, Initial residual = 1, Final residual = 9.01107e-16, No Iterations 1
DILUPBiCG: Solving for Uy, Initial residual = 0.999999, Final residual = 3.23129e-16, No Iterations 1
#0 Foam::error::printStack(Foam:stream&) in "/home/nettis/OpenFOAM/OpenFOAM-1.4.1/lib/linux64GccDPOpt/libOpenFOAM.so"
#1 Foam::sigFpe::sigFpeHandler(int) in "/home/nettis/OpenFOAM/OpenFOAM-1.4.1/lib/linux64GccDPOpt/libOpenFOAM.so"
#2 ?? in "/lib64/libc.so.6"
#3 Foam::PCG::solve(Foam::Field<double>&, Foam::Field<double> const&, unsigned char) const in "/home/nettis/OpenFOAM/OpenFOAM-1.4.1/lib/linux64GccDPOpt/libOpenFOAM.so"
#4 Foam::fvMatrix<double>::solve(Foam::Istream&) in "/home/nettis/OpenFOAM/OpenFOAM-1.4.1/lib/linux64GccDPOpt/libfiniteVolume.so"
#5 main in "/home/nettis/OpenFOAM/OpenFOAM-1.4.1/applications/bin/linux64GccDPOpt/turbFoam"
#6 __libc_start_main in "/lib64/libc.so.6"
#7 Foam::regIOobject::readIfModified() in "/home/nettis/OpenFOAM/OpenFOAM-1.4.1/applications/bin/linux64GccDPOpt/turbFoam"
Errore di virgola mobile

--------------------------------

It seems that the Courant number starts to increase suddenly without reason. I've checked a lot of times the BCs and they seems to be correct.
Indeed I've analyzed a similar case with Ma=0.75 using rhoTurbFoam, and there was no problem.
I hope somebody can help me.
Thank you in advance.

LN

ps: I've set the turbulence off in this case. However I've tried with turning it "on" as well, and the behaviour is the same.