[CsabiH]

Hi!

I think it's a noob question but I cannot find the "why".
I was trying to run the same simulation (NACA 2412 airfoil with different AOAs) with k-Epsilon and k-OmegaSST. For the k-Epsilon I was able to run all of my simulation (between AOA 0°-18°), but for the SST all was failing (The simulation files is here: https://github.com/HetyCs/space/blob/master/sst2.zip )

Does it happen with anyone else? Maybe somebody know why it's happen?

Details:
Mesh are imported from Fluent, I run in steady state, some details came from the OpenFOAM's arifoil tutorial others from various sources (finding with google).

First time when I run in parallel, I got always this message (I was tried to run in 8, 4 and 2 core on two different PC):

Time = 7

DILUPBiCGStab: Solving for Ux, Initial residual = 0.6190897, Final residual = 0.01558434, No Iterations 2
DILUPBiCGStab: Solving for Uy, Initial residual = 0.6421446, Final residual = 0.03402597, No Iterations 2
DILUPBiCGStab: Solving for Uz, Initial residual = 0.01623852, Final residual = 0.001378081, No Iterations 1
GAMG: Solving for p, Initial residual = 0.2421197, Final residual = 0.02305116, No Iterations 4
GAMG: Solving for p, Initial residual = 1, Final residual = 0.005137695, No Iterations 1
time step continuity errors : sum local = 6.253806e+25, global = -5.842945e+10, cumulative = -5.842945e+10
DILUPBiCGStab: Solving for omega, Initial residual = 0.5883746, Final residual = 0.01695568, No Iterations 1
bounding omega, min: -9.2748e+17 max: 3.077731e+18 average: 1.562023e+14
DILUPBiCGStab: Solving for k, Initial residual = 0.2610974, Final residual = 0.01608745, No Iterations 1
ExecutionTime = 12.19 s ClockTime = 12 s

Time = 8

DILUPBiCGStab: Solving for Ux, Initial residual = 0.7223081, Final residual = 0.05084051, No Iterations 1
DILUPBiCGStab: Solving for Uy, Initial residual = 0.7184469, Final residual = 0.0513341, No Iterations 1
DILUPBiCGStab: Solving for Uz, Initial residual = 0.7743565, Final residual = 0.05029539, No Iterations 1
-------------------------------------------------------
Primary job terminated normally, but 1 process returned
a non-zero exit code.. Per user-direction, the job has been aborted.
-------------------------------------------------------
--------------------------------------------------------------------------
mpirun detected that one or more processes exited with non-zero status, thus causing
the job to be terminated. The first process to do so was:

Process name: [[53576,1],0]
Exit code: 142
--------------------------------------------------------------------------
cs@DESKTOP-2DMKBPC:~/OpenFOAMW/sst2$

When I try to run in serial, the simulation ended at the 8th iteration without any error message.

Time = 7

DILUPBiCGStab: Solving for Ux, Initial residual = 0.6844985, Final residual = 0.05382421, No Iterations 1
DILUPBiCGStab: Solving for Uy, Initial residual = 0.6899303, Final residual = 0.04158705, No Iterations 1
DILUPBiCGStab: Solving for Uz, Initial residual = 0.6400409, Final residual = 0.06345476, No Iterations 1
GAMG: Solving for p, Initial residual = 0.334632, Final residual = 0.0265109, No Iterations 3
GAMG: Solving for p, Initial residual = 1, Final residual = 0.03916845, No Iterations 1
time step continuity errors : sum local = 3.808465e+24, global = -1.037842e+09, cumulative = -1.037842e+09
DILUPBiCGStab: Solving for omega, Initial residual = 0.03670445, Final residual = 0.003059216, No Iterations 4
bounding omega, min: -2.270383e+16 max: 3.898286e+16 average: 1.93997e+13
DILUPBiCGStab: Solving for k, Initial residual = 0.1322971, Final residual = 0.007287265, No Iterations 1
ExecutionTime = 11.64 s ClockTime = 12 s

Time = 8

DILUPBiCGStab: Solving for Ux, Initial residual = 0.7391198, Final residual = 0.0301078, No Iterations 1
DILUPBiCGStab: Solving for Uy, Initial residual = 0.7285467, Final residual = 0.03929454, No Iterations 1
DILUPBiCGStab: Solving for Uz, Initial residual = 0.7519563, Final residual = 0.0528125, No Iterations 2
cs@DESKTOP-2DMKBPC:~/OpenFOAMW/sst2$

[yambanshee]

Looking at your pressure residual, you are getting a diverging solution. What is your mesh quality parameters (run the command checkMesh in the case dictionary) and your boundary conditions?

[mzzmrt]

Your case has many problems such as boundary conditions and mesh.


You have a 2D (pseudo 3D) case and you have to use "empty" boundary condition for sides not "symmetry". Also be careful for inlet and outlets etc.



You can check the airfoil2D case for a correct setup.



For meshing this type of work it's far better to use another open-source tool "Construct2D" instead of Gmsh.

[CsabiH]

Dear mzzmrt and yambanshee,
Thanks for your ideas. I could run the simulations with new solver options and the empty BC.
Thank you