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-   -   simpleFoam time step continuity errors (http://www.cfd-online.com/Forums/openfoam-solving/124922-simplefoam-time-step-continuity-errors.html)

CUBoulderPhDStudent October 15, 2013 16:39

simpleFoam time step continuity errors
 
I'm running a simple laminar case using simpleFoam and low Reynold's number (around .01) with a very large domain. My system is 140000nm by 8000nm with mesh points around every 5nm. I've got a rectangular grid imprint on the bottom of the membrane and the domain is decomposed using scotch method into 48 domains.

I keep on running into errors where the "time step continuity error" goes to infinity. I've run "checkMesh -allGeometry" and the mesh comes back fine.

I have no slip on the imprinted membrane.
Pressure uniform 0, and zeroGradient velocity on the outlet.
The top is open to the rest of the fluid but I know the velocity profile along the surface and set freestream velocity and pressure on the surface.
Inlet I only had 6 data points but it was pretty uniform so I have uniform fixed value velocity there and zeroGradient on pressure.

I've tried a bunch of other boundary conditions, but no matter what the "time step continuity error" always explodes. Does anyone have any ideas or suggestions to try?

Thank you

Daniel_Khazaei October 15, 2013 17:06

As far as I know simpleFoam is a steady-state solver! (1.6-ext)

How could you have time step continuity error?


regards

CUBoulderPhDStudent October 15, 2013 17:14

It is a steady state solver. That's particularly what's disturbing. From the other threads I looked at, when this error occurs with simplefoam its either a mesh problem (which I checked) or its a turbulence model problem (and I'm laminar) and there was one boundary problem that involved periodic boundaries.

Daniel_Khazaei October 15, 2013 17:19

Quote:

Originally Posted by CUBoulderPhDStudent (Post 457157)
It is a steady state solver. That's particularly what's disturbing. From the other threads I looked at, when this error occurs with simplefoam its either a mesh problem (which I checked) or its a turbulence model problem (and I'm laminar) and there was one boundary problem that involved periodic boundaries.

I think that should mean the continuity error or someone correct me?:rolleyes:

Have you checked the boundary conditions?

it would be better if you could share a log file of your simulation.


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