[alkochevsky]

Hi dear OpenFOAMers,
I am trying to generate streamlines in Paraview in some domain where I have just simulated the fluid flow. As far as I see, the only possible seed types (where the streamlines will have their origins) are Point Source and Line Source. For me it would be quite naturally, however, to generate streamlines starting, for example, from the inlet, i.e., by taking it as an area source. Is it possible in Paraview? I work now with the version 3.8.0, under Linux SuSE 11.

Regards,
Alexey Kochevsky

[MartinB]

Hi Alexey,

it is possible in Paraview:

- Separate your inlet face (for example via foamToVTK or File->Save Data or Filters->Alphabetical->Slice ...) so that you have it listed in the Pipeline Browser as a selectable object.
- Select filter "Filters->Alphabetical->Stream Tracer With Custom Source", as "Input" select your simulation results, as "Source" select your inlet face.

Martin

[alkochevsky]

Hi Martin,
thank you very much, it is exactly what I needed. Paraview seems to be still more powerful than I thought before.

Regards, Alexey

[Islam ElQatary]

Originally Posted by MartinB

Hi Alexey,

it is possible in Paraview:

- Separate your inlet face (for example via foamToVTK or File->Save Data or Filters->Alphabetical->Slice ...) so that you have it listed in the Pipeline Browser as a selectable object.
- Select filter "Filters->Alphabetical->Stream Tracer With Custom Source", as "Input" select your simulation results, as "Source" select your inlet face.

Martin

how to make streamlines like in the pic

[wyldckat]

Originally Posted by Islam ElQatary

how to make streamlines like in the pic

Sorry for the reaaaaaally late reply, but I only found out about this recently - what you're looking for is the "surfaceLIC" plug-in: http://www.cfd-online.com/Forums/par...ic-plugin.html

[t.oliveira]

Hi,

I have created streamlines from an area source, but the results is far from the expected. This is the pressure field of the flow through a cubic sample of rock. Inlet is at left, outlet at right. All the other four faces are walls.
1.png


I can display velocity vectors coloured by their magnitude. Then, I extract a plane near the inlet and use it to create the streamlines:
2.png 3.png 4.png

As you can see comparing the streamlines with the velocity field, the streamlines don't show the trajectories that lead the fluid from the inlet to the outlet, let alone the two high speed paths that can be seen in the velocity field image.

I have already tried tweaking the properties of the streamlines in all ways I could imagine.

Do you have any suggestion on how to display them properly?

Thanks, Thomas

[wyldckat]

Greetings Thomas,

I've had your question on my to-do list for quite some time now and I've finally come to it. Fortunately, I found about this issue and the solution for it a few days ago as well, which I'll quote from where I found it (link in the quote):

Originally Posted by taalf

As I though, the problem came from the polyhedral nature of the mesh.

The use of the Tetrahedralize filter allowed to convert it into a tetra mesh, on which the Stream Tracer filter works perfectly.

Best regards,
Bruno

[t.oliveira]

Bruno,

Thank you for your suggestion, which was very useful!

I would just like to register here, for future readers of the post, that in Paraview v.4.4.0 I am now able to visualize the streamlines without recurring to the Tetrahedralize filter.

[jf_vt]

Hi
When using steam tracer with custom source I dont see the ability to set the length of the line and their number.
Is there any way to do it?
Thanks
JF

[t.oliveira]

Hi JF,

I am using Paraview v.4.4.0.

Regarding the length of the line, on the "Properties" tab of the stream tracer with custom source, the white gear that is at the right of the "Search" field toggles advanced properties. If you toggle it on, you will see on the "Properties" section of the "Properties" tab the settings related to the integration step length, maximum steps and maximum streamline length.

I couldn't find setting related to the number of streamlines. I believe this is something to be set on the object used as a source, and not on the streamline.

Best regards,
Thomas

[jf_vt]

Thank You Thomas I am not sure how long it will have taken me to figure that out on my own

.... I am still looking for settings the number of streamlines

JF

[Juzzvy]

Hello everyone, How can I produce multiple streamline "seeds" (i don't know the term) using the streamline in system? I can only produce one streamline. Thank you

[Deagle]

Maybe this will help someone:
To create multiple streamlines from a slice, but not from all cell centers in a slice, first create a slice from where you want to initiate the streamlines.
Next, use the filter MaskPoints and set a certain amount of points can be place at random).
Then use the Stream Tracer With Custom Source as mentioned above with the MaskPoints as source.

This will create a number of streamlines from the slice, in which you can determine the amount of tubes yourself.

[Rasmusiwersen]

Originally Posted by MartinB

Hi Alexey,

it is possible in Paraview:

- Separate your inlet face (for example via foamToVTK or File->Save Data or Filters->Alphabetical->Slice ...) so that you have it listed in the Pipeline Browser as a selectable object.
- Select filter "Filters->Alphabetical->Stream Tracer With Custom Source", as "Input" select your simulation results, as "Source" select your inlet face.

Martin

Martin, one of the best suggestions i've ever read.. This has saved me so much time and made it possible for me to visualize flows in a completely different way. Thank you!

[schnafkid]

Originally Posted by Deagle

Maybe this will help someone:
To create multiple streamlines from a slice, but not from all cell centers in a slice, first create a slice from where you want to initiate the streamlines.
Next, use the filter MaskPoints and set a certain amount of points can be place at random).

Thats a real cool approach to randomize the seed points. However, I couldn't manage to get seed sources off the already existing vertecies on the inlet patch.


I stumbled upon this other approach, where you slice the seed patch multiple times (using the 'add a range of values' button in the advanced properties of slice) in in y and z direction (if inlet normal points in x direction). See https://www.youtube.com/watch?v=4IA62XElbfI&t=651s "Streamlines With Patch Seeds ∇ ParaView®" by Holzmann CFD.


That way, you get a new grid of seed points without beeing bound to your original vertex number on the inlet. It's kind of hard to determine the number of seed points if you don't have a rectangular inlet patch, though. And, the distribution isn't really random that way...


For my problem, I should have a random distribution of seed points on the inlet, and way more than mesh vertecies... Anyone an idea...?