Help to plot the streaklines from OpenFOAM simulation

ParaView Support
1

Hi all,
For the couple of weeks I am trying to plot the streaklines from my 3D simulations that I have performed using OpenFOAM. I got the streamlines working, but when ever I am trying to plot the streaklines, and tried to set the integration time to the last time of simulation, the paraview (5.8.0) crashes and gives the segmentation fault. Could any please help in this regard. Could any body please share the pipeline that has to be used to plot the sreaklines for the flow pattern. Any comment/suggestion will be a great help. Thanks in advance.

2

Streaklines works fine if you have timesteps, make sure to set the TerminationTime to something greater than 1.

Please share your dataset if you need further help.

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3

Thanks a lot Mathieu Westphal for your prompt reply and help. I tried to changed the Termination time to 10, since the last time step corresponds to time =10, but it didn’t work, nevertheless I forgot to mention that there are no actual particles in the flow, and only velocity of the flow is there. The data set is too heavy for sharing (it’s in some GBs, since the mesh is itself a heavy one approx. 500 MB) so I am afraid that I will be able to do that. If possible could you please share the pipeline of doing so. Meanwhile I am now successful in plotting the “particles” from the filter “TemporalParticlesToPathlines” (not the pathlines, since it messes up heavily and I am unable to figure out anything). So I think I am close but not exactly what I need. Thus any further comment/suggestion will be a great help. Thanks a lot again for your kind help.

4
  1. Do you actually have timesteps on your data ?
  2. You definitelly needs to define some seeds, use point source for that
  3. Are you looking for Pathlines or Streaklines ?
  4. Take a look at this, even though streaklines are not covered, the usage is very similar as the second part of the webinar: https://vimeo.com/477251491
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5

Wow, thanks again Mathieu Westphal for your quick reply. I think the video is quite informative I will look and revert back to you, answers to your questions:

  1. Yes I have multiple time step data varying from 0 to 10 in the interval of 0.1
  2. For seeds (at least for the streamlines option of “streamTracer with custom source” ) I am inputting one block as “SeedSource”.
  3. More interested in Streaklines.
  4. The video looks interesting and working on that, thanks for sharing.
    Many thanks for your quick reply and help. :slight_smile:
6

Hi Mathieu Westphal,
I went through the video, it was really helpful and amazing, now at least I am able to plot streaklines without the “segmentation” error although it’s still not making too much sense to me, but anyways it was really helpful. Actually I want to seed not through the point source rather wanted to seed from the block (using extract block). So instead of having lot of particles in the sphere I want the particles to start from a certain block and then traced through the streaklines. Do you think it’s doable in the ParaView?

7

Yes, that sounds absolutely doable, just select the point you want to use as seed, then use ExtractSelection to recover for them.

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8

Hi Mathieu Westphal,
Thanks again for your prompt reply, as per your suggestion, I tried to select the points from the block and then extracted those points through the ExtractSelection, but unfortunately again using this as a seed in the streakline it crashes. Just to recall, this issue was rectified when I was either using sources as — point source or line source . Am I missing something ?

9

Hard to say without access to your data tbh.

10

Instead I want to ask a rather straightforward scenario, I have successfully applied the “Stream Tracer with Custom source” using the “Seed Source” as an inlet block from the “ExtractBlock” utility. In the similar fashion if I am trying to plot the streaklines using the same “Seed Source” but it crashes. My question is:
Are the two “Seed Source” different for “Streamlines” and “Streaklines”? And if yes, then what’s the difference between them? Any comment/suggestion will be a great help.

11

The code is not the same. Maybe there is bug in streakline filter, maybe there is a problem with your dataset that only matters when using the streakline filter. To be able to help, I need a dataset to try for myself. You can try reproducing your issue with a smaller dataset that you can share.

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12

Hi Mathieu Westphal,
Thanks for your reply, actually when I decreased the resolution for a plane to be input as a “Seed Source” the sreakline worked. I guess that the streakline requires very high computations since it needs integration from one time to another time, thus the sreakline was crashing (segmentation fault). Now I have the streakline but it is not advancing in time instead it gives me a final snapshot of the streakline plot. How to make a video of the streakline, do you have any idea?

13

This is not supported by streaklines. This mode is supported by the Particle Tracer, as shown in the video.

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14

Great, thanks for clearing the doubt, so if I want to plot the streaklines, it will always show the final snapshot and won’t show the time progress (video). Is there any way to have a time progress of a streaklines? Anyways thanks a lot for your consistent time and help.

15

You could do something similar to the animated streamtracer I show in the webinar I link earlier.

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16

Ok, thanks a lot Mathieu Westphal for you kind help and support