Floating Point Error Caused By Large Residual

ss32 · April 10, 2016, 16:11

Quote:

Originally Posted by tas38

If you post an external link of your full case directory, I can quickly try to run in 2.3.0 and see what errors it throws.

I think this may be the quickest way to track down the issue.

Done. This is sitting in $FOAM_TUTORIALS/incompressible/simpleFoam/

https://www.dropbox.com/s/7h1wljfb04...auert.zip?dl=0

Thanks again for all the help

tas38 · April 10, 2016, 17:08

Got it to run after a few tweaks. Most notably, changed the pressure solver to PCG to get simpleFoam to proceed a few iterations.

Take a look at the solution after a few iterations, I think the issue resides with the mesh, even so it passes checkMesh.

https://www.dropbox.com/s/rkxw0qqk5l...rtMod.zip?dl=0

ss32 · April 10, 2016, 17:14

Great! Looking at the velocity data I'm thinking it's an issue where the grid folds over at the trailing edge and there's a huge discontinuity. That's a huge help and now I know what to work on.

ss32 · April 10, 2016, 17:22

You say you changed the pressure solver to PCG, where do I make that change? And did you change the turbulenceProperties? I see the old one but yours is missing.

tas38 · April 10, 2016, 17:26

Pressure solver changed in fvSolution file.

Older version (2.3.0) of OpenFOAM uses RASproperties file in lieu of the turbulenceProperties file in v.3.

I only ran a laminar case.

To run in v.3., revert to your original setup with a turbulenceProperties file and no RASproperties file.

ss32 · April 10, 2016, 17:32

It's a start, I got the first two time steps before it blew up this time. Awesome, I'll get to work on the mesh, thanks man.

ss32 · April 10, 2016, 17:57

It works! With an O-grid! Jesus what PITA. I'll go back and work on the C-grid but for now I can make some progress

tas38 · April 10, 2016, 17:59

Good stuff.

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April 10, 2016, 17:08		#22
tas38 Senior Member Troy Snyder Join Date: Jul 2009 Location: Akron, OH Posts: 220 Rep Power: 19	Got it to run after a few tweaks. Most notably, changed the pressure solver to PCG to get simpleFoam to proceed a few iterations. Take a look at the solution after a few iterations, I think the issue resides with the mesh, even so it passes checkMesh. https://www.dropbox.com/s/rkxw0qqk5l...rtMod.zip?dl=0

April 10, 2016, 17:14		#23
ss32 Member Join Date: Apr 2016 Posts: 39 Rep Power: 10	Great! Looking at the velocity data I'm thinking it's an issue where the grid folds over at the trailing edge and there's a huge discontinuity. That's a huge help and now I know what to work on.

April 10, 2016, 17:22		#24
ss32 Member Join Date: Apr 2016 Posts: 39 Rep Power: 10	You say you changed the pressure solver to PCG, where do I make that change? And did you change the turbulenceProperties? I see the old one but yours is missing.

April 10, 2016, 17:26		#25
tas38 Senior Member Troy Snyder Join Date: Jul 2009 Location: Akron, OH Posts: 220 Rep Power: 19	Pressure solver changed in fvSolution file. Older version (2.3.0) of OpenFOAM uses RASproperties file in lieu of the turbulenceProperties file in v.3. I only ran a laminar case. To run in v.3., revert to your original setup with a turbulenceProperties file and no RASproperties file.

April 10, 2016, 17:32		#26
ss32 Member Join Date: Apr 2016 Posts: 39 Rep Power: 10	It's a start, I got the first two time steps before it blew up this time. Awesome, I'll get to work on the mesh, thanks man.

April 10, 2016, 17:57		#27
ss32 Member Join Date: Apr 2016 Posts: 39 Rep Power: 10	It works! With an O-grid! Jesus what PITA. I'll go back and work on the C-grid but for now I can make some progress

April 10, 2016, 17:59		#28
tas38 Senior Member Troy Snyder Join Date: Jul 2009 Location: Akron, OH Posts: 220 Rep Power: 19	Good stuff.