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Floating Point Exception/Meshing/Temp Issue

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Old   December 29, 2017, 17:05
Default Floating Point Exception/Meshing/Temp Issue
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I tried various solutions found in the forum to similar errors to this:

Quote:
Temperature limited to maximum value 29491 times on model-part "Region 1"
Temperature limited to minimum value 2478853 times on model-part "Region 1"
Minimum Temperature limited to 5.37222 on 3693 faces on Tank
Maximum Temperature limited to 477.594 on 547 faces on Tank
16 2.071292e+24 1.584849e+23 3.791489e+21 2.224511e+23 2.083516e+33
WARNING: insufficient precision on multigrid level 3, nRows = 52234
AMG coarsening halted.

Bi-Conjugate Gradient Stabilized solver did not converge !
Reversed flow on 73 faces on Outlet
Obviously after about 8 iterations the simulation blows up and says "Floating Point Exception [Divide by zero]"

I read that the issue lies within the temperature error. I don't quite understand how to resolve this. I ran a diagnostics on my mesh and it appears to check out. I'm trying to simulate -440F gas going into a tank. My max and min temps are set to -450F and 400F.

Any suggestions on what might be occurring here?
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Old   January 2, 2018, 03:57
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There can be many possibilities like mesh, solver etc. Need detail problem description and error report to comment something valuable. First if you are sure that mesh have no problems then you can check solver errors. Try retain temporary storage option to see which solver is starting the divergence.
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Old   January 2, 2018, 17:45
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Thanks Ashok,

I appreciate the help. So I fixed my mesh, and now I don't get the zeropoint error.

However, I'm getting extremely high velocities at random points in my container.

I have a spherical container where the fluid enters at the top through an inlet with 100 small orifices about .2 in in size. The inlet condition is mass flow at 3 lb/s. I didn't play with the temperatures. The Physics is Constant Density, Gas, Implicit unsteady, laminar, segregated flow, 3D.

My inlet seems to be a reasonable value, but I get these large velocity spikes on the surface (see pictured). Do you have any suggestions on what might be causing these unrealistic velocity spikes in the solver? These spikes only occur in a single place per iteration (the spike moves around the geometry), the rest of the solution looks as expected.
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Old   March 30, 2020, 12:34
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Quote:
Originally Posted by swadejaxsun View Post
I tried various solutions found in the forum to similar errors to this:



Obviously after about 8 iterations the simulation blows up and says "Floating Point Exception [Divide by zero]"

I read that the issue lies within the temperature error. I don't quite understand how to resolve this. I ran a diagnostics on my mesh and it appears to check out. I'm trying to simulate -440F gas going into a tank. My max and min temps are set to -450F and 400F.

Any suggestions on what might be occurring here?
Hello,swadejaxsun
Have you sovled the problem? I meet a similar problem as yours.
The report is as follows:
Wall distance limited to 1e-06 on 9 cells in innerField

Computing Acoustic Suppression Zone boundary distance .. end.

WARNING: insufficient precision on multigrid level 11, nRows = 284
AMG coarsening halted.

Bi-Conjugate Gradient Stabilized solver did not converge !
WARNING: insufficient precision on multigrid level 10, nRows = 1133
AMG coarsening halted.

Error: AMG solver diverged.
A floating point exception has occurred: floating point exception [Invalid operation]. The specific cause cannot be identified. Please refer to the troubleshooting section of the User's Guide.

Thanks in advance, It is very appreciated if you can give me some advice!
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