- A description of the project and what you are trying to achieve
I am trying to understand the behavior of the wind behind a tree (a tree is standing in front of a traditional windmill and I would like to understand its influence). Using incompressible (air) fluid flow model (in the free SIMSCALE plan).
The tree is a 70 year old oak (top of canopy some 15.5m) and its some 25m from the traditional windmill (which is 14m high).
Can I simulate such a tree with a cylinder and spherical blob above it? I think the stem’s cylinder is straight forward (around 0.5cm in diameter and 3.5m high), but the spherical blob will be depending on the season (say summer and winter time). What would be the size of the blob if I know the size of the leaved/unleaved tree? Is there some kind of relation. Sometimes I hear the porous in the Advanced concepts (i don’t see it in the Advanced concepts, I assume I need professional licence). The porous media would be 0 in summer and in winter say 0.5.
But can I simulate the tree in (perhaps a slightly less way) in the free SIMSCALE plan?
Thanks for your help (SIMSCALE project examples, literature, article links, etc).
All the best,
Victor
Hi @molen_victor,
This is the case where the CAD file should be more intricate than the simulation. Here I leave a good simulation of a tree using incompressible analysis type. You can make a copy, use the same geometry, upload your own geometry, use it as guide or even change parameters just to see how it goes:
best,
Thanks or this! As I am new in SIMSCALE, I am wondering how I can get the tree-model out of your project. I use SketchUp for my modelling, so I would like to use that to make changes… I think I only see the ‘Flow region’ and not the tree-object itself. Correct, or do I miss something?
<‘Edit in CAD mode’ is ‘greyed’ out>
At this moment I made a stylised leaved tree: several disks upon each other:
The resulting flows mimic what I see in this article (file:///C:/Users/nlvic/Downloads/atmosphere-14-01010.pdf ), except my flow velocities are slightly higher (say 1m/sec):
<the grey lines [with a number] are the velocities from the article (its Figure. 16), while the colors are the SIMSCALE results of my tree model.
Thanks again for your help.
All the best,
Victor
Hi again @molen_victor,
You can download any geometry from any public project just clicking on the icon down below:
You are seeing the flow region, and if you click on any face of the flow region and then click on ‘‘Hide Selection’’, you will be able to see the tree in the flow domain.
best,
Thanks. I have the tree now downloaded. Sorry, that I did not sop this download symbol earlier!
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That worked, I now have compared the velocity contours (in the y-plane at the stem of the tree). i already gave the contours in my earlier e-mail). Here it is for your tree:
So the form of the velocities is closer to the article’s Figure 16, which I quoted earlier, but the values are still 1m/sec higher in the simulation than in the article. Of course I don’t know myself what is reality;-)
Any thoughts. Could the drag be the reason?
Can i include this drag in some way into SIMSCALE? Sorry for all these questions.
All the best,
Victor
By the way, is there a good (representative) leafless tree model for SIMSCALE?
Perhaps I can generate something myself, but I would need something that would be able to stand ‘scientific’ scrutiny;-) And I am not experienced enough (yet) to determine the validity.
Thanks.
Hello Goncalves,
Is it possible that yur tree has intersecting surfaces? I understand SIMSCALE wants as much merged objects (so no intersecting surfaces). There are some times situations that the tree (while I scaled it thinner and longer) gives a velocity error when simulating (velocities of say 1E+6). If I move the tree slightly around, this error goes away. My SketchUp (free version) does not allow cleaning up (merging); would you be able to provide such a merged tree? Or do you know if there is a free tool do do that? Thanks.
All the best,
Victor
Hi @VictorReijs,
You can go to the CAD Mode and use Boolean operation to make an union or intersection. Please read this article to know how to do it:
best,
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I think that I might have described my problem wrongly. But thanks for your link to that page, very helpful! Reading that page, I think I was talking about ‘Selfintersections’. For instance in the (scaled) tree a few blobs are overlapping (aka selfintersecting) and also the branches pierce into the blobs. So I think that ‘Wrap’ might do the job in SIMSCALE. I will try this next time I simulate and get this ‘velocity’ issue.
All the best,
Victor
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