Iterations stopped for long time - Simulation CFD 2015

[archNUOVO]

Hello Everyone,

I'm wondering why the simulation stopped running for long time at the 'Iterations' dialog box. I guess the meshing process is complete. Meshing took nearly Four Days.

Also, almost all RAM (16 GB) power is underutilized.!!!

Screenshot attached.

Can anyone help me with this?

Regards,

Tanvir M

[marwan_azzam]

Hello Tanvir,

If meshing took four days to complete I'm guessing the element count is very high.  If so, it might be taking a very long time for one iteration to complete.

1- How many elements does your model have?

2- Open Windows Task Manager, go to the Processes tab and see if CFDSolver is running

[archNUOVO]

Hello Marwan Azzam,
Thank you very much for your reply.

SimCFD.exe and 'Autodek Application Manager' is running and not the 'CFDSolver'.
In this case, what can I do?

My elements count is 5550829.
In fact, I am running the same calculation (almost) in two PCs. I'm saying 'almost', as I'm just checking the difference in results between 'layer' counts.

Both tend not to solve for a long time. Even though, at one point the 'iterations' run for several count and stopped due to a power glitch. 

I'm assuming the following shall be true for any SimCFD case:
1. Meshing - CFDMesher.exe should run.
2. Iterations - CFDSolver.exe should run.
Please correct me if I'm wrong.

I guess it would be great, if Autodesk includes 'percent count' for different processes of 'meshing' and 'solving' for a visual cue. Probably, it is not listed in IDEA Station yet.

Regards,

Tanvir

[marwan_azzam]

Hello Tanvir,

5,550,829 elements does not seem that high.  I wonder why it took so long to mesh.

Are you running and saving  everything on the local machine.

You are right:

SimCFDMesher.exe will be running during meshing, and

SimCFDSolver.exe will be running during the analysis.

[archNUOVO]

Hello Marwan,

No wonder, I thought so before - the meshing shouldn't have taken so long. I'm running all on the local machine. 

Any idea how I can debug this?

Thanks for your help.

Regards,

Tanvir

[Jon.Wilde]

Hey, I had a thought.

Did you draw the air box in CAD?

If it was done in CFD, you would have a really thin gap beneath the model - not sensible and would take longer to mesh.

If you use the mesh diagnostics, are there any thin surfaces that need fixing in CAD?

[archNUOVO]

Hello Jon,

Thanks for your thought. I made the model with AutoCAD.

Simulations ran previously without any problem, until the power glitch happened. What causing it to take long than usual, is need to be solved.

However, mesh diagnostic could be an option that I need to check.

I will update you.

Thanks again.

[Jon.Wilde]

Hey,

Did the diagnostics help to identify meshing issues?

Or is all OK now?

Thanks,

Jon

[archNUOVO]

Hello Jon,

Thank you for the reply.

Yes, I modelled the air box in CAD and the Gap Refinement options is not explored yet. You know the simulation ran at first instance and ran up to 300 iterations.

I may need to explore different avenues.

Regards,

Tanvir