[KTG]

Hello all,


I would like to add some particle tracks to a pimpleFoam simulation. Just passive tracers - no mass or volume - to get some pathlines in an LES simulation. This seems like a really basic thing, but I always find empty threads of people trying to figure this out. It seemed like this function object was the answer, but I can't find an example of its usage anywhere! I put this in the control dict:

tracks
{
libs ("liblagrangianFunctionObjects.so");
type icoUncoupledKinematicCloud;

}


and kinematicCloudPositions in constant/ with two points in it inside the T junction tutorial. I get:


request for singlePhaseTransportModel transportProperties from objectRegistry region0 failed
available objects of type singlePhaseTransportModel are
0()


Pretty stuck here. Seems like there should be a kinematicCloudProperties file involved, but I don't know what to include with it. Does anyone have a working case file for this? We should add it to one of the LES tutorials for the next release (if anyone knows how to use it).


Thanks-

[KTG]

Maybe I should have said earlier, I would be interested to hear any possible workarounds to getting path lines, short of using the paraview GUI - most simulations are too big for that and I can't write all those time steps.


Thanks

[SimonStar]

Hello KTG,


I am trying to do the same thing than you. Its not nice that so many threads according to that topic stay empty.

I've seen that the visualization of the lines are possible with Paraview. Have you tried this? https://www.youtube.com/watch?v=Dk91aLVpwXc

It would be nice from you to hear if you found a solution so far.


Thank you
Simon

[KTG]

Hi Simon,


I am sorry to say I never found a solution! I have tried using paraview, however this is only a solution for small cases. The problem is that you need to save a lot of files, otherwise you pathlines make angular directional changes and sometimes jump through the corners of solid walls. One of the most frustrating things about working with openFOAM is knowing that something has probably already been implemented, and not being able to figure out where/how to use it.



I was thinking about trying to make a new pimpleFoam solver with this particle class:


https://pingpong.chalmers.se/public/...o?item=4899150


I was not successful. I also considered just running MPPICFoam or DPMFoam with zero mass particles, which would be stupid. I also considered running the passive scalar function object, and then running streamlines through that to get low quality streak lines. What I actually ended up doing was not working on that project for two months - between openFoam and my other job responsibilities, there are plenty of excuses not to.



If you make any progress please keep me informed - I have been trying to get pathlines in openfoam since 2016. Its as if it has never been done before....

[cemf]

Hi,

You may find this link useful.
https://www.cemf.ir/residence-time-d...ticle-tracing/

[KTG]

Thank you - this is exactly what I was trying to figure out. Sorry I didn't notice your post until now. I was grepping the tutorial files for that function object and didn't see anything when I posted that.



Have you considered submitting your tutorials to the openFoam Wiki? I didn't see them there. The lagrangian parts of openFoam are, in my opinion, pretty difficult to get started with and there are not many resources out there for us non-experts.

[KTG]

I did have a question about the tutorial: did you make that figure with the pathlines in paraview? I saw that particle tracks can be done there, but wasn't sure if there was a way to do them with openFoam's function objects so that I could get smooth tracks without having to write a lot of time steps?