SimScale CAE Forum

Creating Topological Entities for the mesh


I am new user to SimScale and I was trying to simulate flow through wind turbine. I copied this project from @jprobst. The link to my project is

I am having issues to create Topological entities during mesh. The geometry does not have any inlet section or outlet section. It just has the wind turbine. But, it is necessary to various inlet/outlet sections before the mesh. I am unable to create them as I see no option. It is done in “wind-turbine mesh” mesh, but I do not know how (because I just copied it :stuck_out_tongue: ). So if somebody can tell how to create them during the mesh process, it will be really nice.

PS: I have tried directly the mesh operation without creating the inlet. But the mesh is only made on the wind turbine and not outside of it.

Thanks in advance
Abhishek VERMA

Hi Averma,

I usually define inlets and outlets and the rest of the BCs after the mesh is done. The topological features created before the mesh are usually more for defining different mesh regions of different constrains. For a turbine blade you would want to do an external mesh and then you define the faces during the simulation designer section. I recommend you try some of the homeworks and tutorials to get more used to Simscale. Here’s a good post for that:

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Hi @averma,
as mentioned by @oscarcorripio the inlet and outlet faces will only show up after the meshing was done. There are 2 meshing algorithms which will create the box for you:

  • Hex-dominant automatic for external flow (only CFD)
  • Hex-dominant parametric (only CFD)

Both have a box named “_BaseMeshBox” which sets the dimensions of the background mesh, respectively the location of the inlet and outlet faces. This is also demonstrated in the tutorials posted above.

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Thank you @jprobst and @oscarcorripio for your replies. You were right that we need to create topological entities after the mesh. I made a mistake earlier and kept the material point inside the CAD model and was unable to create an external mesh. This is why I got confused and thought we need to define the boundaries (topological entities) during the meshing phase. But later, I was able to make the mesh. Once again. thank you. :smiley: