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-   -   [OpenFOAM] Paraview doesn't seem to be picking up data generated by icofoam (https://www.cfd-online.com/Forums/paraview/146756-paraview-doesnt-seem-picking-up-data-generated-icofoam.html)

MikeHersee January 6, 2015 07:41

Paraview doesn't seem to be picking up data generated by icofoam
 
I'm running the first tutorial on OpenFoam, here: http://openfoam.org/docs/user/cavity.php#x5-40002.1 . I've followed the instructions in that I've run 'blockMesh', and that produces reasonable-looking output (to my untutored eye). I've run paraview in batch by doing 'paraview &', and following the instructions to look at the mesh, I get the same picture as the tutorial (even though with a later version of paraview, v 4.1, and the display tab is merged with properties, and the colours are slightly different.)

Then I run icoFoam, and it runs for a second or so, and produces a final set of data in the terminal window that looks like this:

Time = 0.5

Courant Number mean: 0.222158 max: 0.852134
smoothSolver: Solving for Ux, Initial residual = 2.32737e-07, Final residual = 2.32737e-07, No Iterations 0
smoothSolver: Solving for Uy, Initial residual = 5.07002e-07, Final residual = 5.07002e-07, No Iterations 0
DICPCG: Solving for p, Initial residual = 1.0281e-06, Final residual = 2.77237e-07, No Iterations 1
time step continuity errors : sum local = 4.0374e-09, global = -9.0204e-19, cumulative = -2.44407e-18
DICPCG: Solving for p, Initial residual = 5.31987e-07, Final residual = 5.31987e-07, No Iterations 0
time step continuity errors : sum local = 6.12557e-09, global = -3.93738e-20, cumulative = -2.48344e-18
ExecutionTime = 0.49 s ClockTime = 1 s

End


So that looks ok, although the numbers look a bit on the low side to me, and I have no idea whether the courant numbers are reasonable or not. When I return to the paraview window which is still open, the instructions say I should click on 'refesh times' to load the generated data, which I do. However, according to the data range axis the range is between 0 and 1e-16 - ie, while I'm not a mathematical genius, it appears to me that the numbers for pressure range between approximately zero and zero and I effectively get a solid coloured box the same throughout. On the colour map editor, under 'mapping data' it says, "data range too small to render". According to the example in the tutorial, the pressure data range should be somewhere in the range of -4.4 to 4.88.

So it looks to me as though paraview is not picking up the data that icoFoam has generated. But then, where is the data? I went looking for a suitable file and couldn't find anything that had any thing that looked like data in it. Both icoFoam and paraview were initiated from the same session and the same directory that the tutorial says to use. So where is the data stored that icoFoam generates?

Any help in getting over this hurdle also - which I'm sure won't be the last - would be much appreciated.

** UPDATE ** ok, I've found the data output by icoFoam, I've just realised it is output by tenth of a second in this instance, and each tenth of a second is stored in a separate directory by the looks of it, but how can I get paraview to load the data? I can't seem to find a way to load the relevant 'P' or 'U' file.

alexeym January 6, 2015 08:06

Hi,

You've updated time step data with 'Refresh times' button but still at the first frame (so you're looking at the initial flow field). You should use 'Last frame' button to go to the last time step.

MikeHersee January 6, 2015 08:27

Aha! Now it all works. Thank you very much :-)


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