Elbow with internal formations
 

Hello,

I am trying to simulate water flow in an elbow with internal formations. In the corner of the elbow is attached a rod which is supported by 3 fins. I created the geometry with gambit 2.4.6. There are three main volumes, the two straight pipes (one empty inside and one with the internal formations) and the corner. I wanted to put Boundary Layer on the fin section so I started meshing from there and was ok. The problem is that the corner-volume (with the rod inside) can't be meshed using hex or hex wedge. The only way I could mesh it was using Hex core mesh with tet/hybrid elements ,which leads to a poor quality mesh and I can't use a boundary layer. Is there any way to mesh it with 'better' elements and BL? Maybe dividing the volumes somehow? Any suggestion would be helpfull.

Thank you in advance

Your BL (in white) is not proper defined.
You don't need to attach a BL on internal surfaces, but on outer surfaces (wall)
So in your case pipe-walls, on rod-walls
Regarding tet-hexcore, you can surely fix your poor element.
You can also spit your domain into 3:
-the lower pipe without rod >> meshed with hexa
-the upper pipe with rod >> meshed with hexa
-the elbow part >> with tet-hexcore
This should be quick meshed.

Hello and thank you for your reply. I probably did not make clear that I am interested in checking the effect of the fins and the rod in the flow so in order to have these results I need a boundary layer on the fins which basically are faces without volume and are solved as shadow-walls in fluent. Also the domain is split in three volumes, as I said in my original post, but because of the geometry of the corner it's not possible to use tet/hex and cooper. If the rod was not united to the corner the cooper would work (I tried it). I would like some ideas about making a HEX mesh in the corner volume and also to be able to have BL in the fins-rod-pipe walls. A mesh with Hexcore and tet/hybrid without BL is what I have now.

Thank you again and I apologize for the length of my answer.

ok then forget my BL point, but the other is still available.
I would be surprised if you really have no chance to mesh your corner volume with tet-hexcore.
Could you please post a picture of the place where you cannot mesh it with tet-hexcore