How to create thin surfaces within a solid body using DesignModeler?

Hi all,

I am using Workbench (DM) to set up geometry, using ICEM CFD for meshing (No CFX mesh license) and CFX5.7 to solve the problem. Some internal (thin) walls are needed in my building geometry and I am tending to model them as thin surfaces (0 thickness). If I model the thin walls with a thickness, I can just do it using 'extrude-cut/add materials'. But extruding a polyline sketch as thin surface within a solid body, it doesn't work. My working flow would have to be 'DM for geometry – ICEM CFD for meshing – CFX5.7 for solving'

Your comments are highly appreciated. Regards, Forrest

You can extrude a sketch as a surface applying a zero thickness and choose the "cut material" option. However, for this to work you will have to cut through the entire body.

If you are not cutting through the entire body, you might try extruding it using the "add frozen" option.

Regards, Robin

Robin,

Thank you for your comments. I've tried the method for cutting through the entire body before. Then more than ONE body remained. Tried to link the bodies (for example, two bodies) by drawing a sketch on the adjacent surface of the bodies, extrude using add materials, trying to link them using a hole (for example, the fluid can flow through the hole from one body to the other). But after extruding it, the two bodies are merged together totally, the zero thickness surfaces disappeared. If i cut through it as a thin slot it works after i link the bodies, but this would worsen the mesh quality. Any idea?

Thank you for your help again. If 'add frozen' option works I might be able to add some suspended surface in the geometry to model 'tables with 0 thickness'.

Regards Forrest

Hi Forrest,

Having multiple bodies should not be a problem. ICEM CFD will mesh the surface and maintain a 1:1 connection across it. Just make sure you include a material point in both sides and define the surface as an "internal" surface.

When you import your mesh to Pre, it will display multiple volume regions, but automatically connect them for the solver if they are in the same domain.

Regards, Robin

Hi Robin,

Thank you very much, will try what you suggested here see if i can work this out (may take a while since right now some other stuffs keep me very busy)

Regards, Forrest

Hi, Robin,

Will 'multiple bodies' be a problem for CFX-mesh? Can CFX-mehs also mesh the surface and maintain a 1:1 connection across it?

Thanks!

Jone

Yes. Just make sure the bodies belong to the same part. You can do this in DM by selecting the bodies, then go to Tools>Form New Part.

-Robin

Hi Robin,

I am simulating a cyclone and a part of the top outlet pipe is out of cyclone housing and other part of the pipe is in the cyclone housing. I tried a lot of times but no success. The surface of the internal part can not be meshed. Would you please advice me how to set a material point in both sides and define the surface as an "internal" surface.

thanks Tim