Learning Forum

[simone01]

Hello,

I am using fluent meshing to make the mesh, I found myself very well using Watertight geoometry for the previous geometries, unfortunately I can't use it for the current geometry (I have to simulate the rotation of the impellers in a mixing tank, I'm using the MRF approach so I don't have a clean geometry) I am therefore using the Fault tolerant meshing.

Using watertight geometry on the surfaces of my geometry the polyhedra elements are applied by default, with Fault tolerant meshing the tetrahedra elements instead. Is it possible to mesh the surface with polyhedra elements with Fault Tolerant Meshing?

Thank you

best regards

[Rob]

Fluent Meshing always uses tri mesh when doing the initial surface meshing. When you mesh the volume it remeshes using poly cells. If you have tri cells at the end of the fault tolerant workflow you may have missed a setting. 

No reason why you can't use watertight with impellers with mrf zones. You just need to be careful with the zone definitions. If you want sliding mesh, you could build two models. Look up "append mesh" in Fluent. 

[simone01]

Thanks for the reply.
Then I'll try again using watertight. The problem is that in update boundaries I detected the rotating zone of the impeller and the void of the impeller, but it did not detect all the volume outside the rotating zone. So would you suggest me to do two separate models (for the rotating zone and for the rest of the tank volume) and import them into fluent meshing for the MRF approach? Thank you
Best regards

[Rob]

It should pick up both fluid and the single void zones. If that doesn't work you can try two meshes but not they'll not be conformal in Fluent (read up on mesh interface zones). 

[clmr90]

The same happened to me although with a case of wheel rotation (the zone inside was detected but not the rest of the control volume).  Sadly no solution yet, Hopefully you will find a solution too.

[Rob]

Have you labelled the surface between the two volumes? Did you label the volumes in SpaceClaim? 

[clmr90]

Hi rwoolhou.

I did, I´ll show you the picture. Also I renamed the volumes in Spaceclaim.

[Rob]

Did you use ShareTopology? 

[clmr90]

Indeed, but the strangely the zones (the faces of both interfaces) appeared merged  as you can see in the picture below:

[johan_betancour]

Hello, did you get a solution to this problem?nI need to simulate the rotation of a turbine and I'm trying to use advantages of the watertight workflow, but fluent's manual says I can't make a non conformal mesh with that workflow. Could I get a non conformal mesh with the Fault tolerant workflow?nThanks for your help.n

[Rob]

No, but if you check the other thread there are options. https://forum.ansys.com/discussion/comment/92617#Comment_92617n