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LaunderSharmaKE diverges and return 'nan' error

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Old   July 26, 2017, 17:02
Default LaunderSharmaKE diverges and return 'nan' error
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Vedamt Chittlangia
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Hello,

I am simulating turbulent flow over flat plate using low Reynolds number model: LaunderSharmaKE.

Boundary conditions:
Inlet: U (30, 0 ,0), p 0, k 0.13, epsilon 2.56, nut calculated.
Outlet: zeroGradient
top: zeroGradient
plate: U (0 0 0), p - zeroGradient, k 1e-10, epsilon 1e-8, nut 0.

I am using simpleFoam solver but after running for 14 iterations my solution diverges and I receive an error:
wrong toke type - expected Scalar, found on line 0 the work 'nan'.
When I checked the log files I found that k and epsilon have very large min and max bounds.

Can someone help me resolve this or guide me in the write direction?

Thanks,
Vedant
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Old   July 29, 2017, 10:00
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Fumiya Nozaki
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You might want to check the following points:
1. [Mesh] Y+ value should be at most order of 1 on the plate boundary.
2. [Boundary Condition] Inlet: p zeroGradient, Outlet: p 0

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Old   July 29, 2017, 11:29
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Hello.
Have You tried to set relaxations factor?
Check my post:
Sudden divergence of simulation
Or it could be the mesh problem too.


EDIT:
'nan' means not a number.

Last edited by sheaker; July 29, 2017 at 16:50. Reason: new thought
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Old   July 29, 2017, 16:53
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Vedamt Chittlangia
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Thank you all for your reply.
I think it was a mesh problem. I created a mesh in pointwise for OpenFOAM and used that which was giving me errors. I created a new mesh (using the same parameters as pointwise) using blockMeshDict which was able to converge.
I checked the mesh imported from pointwise using checkMesh and found no errors. My y+ was 0.3. So, I don't understand what was the problem with the previous mesh?
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divergence, low re k-e, openfoam 2.2.2, turbulence modeling

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