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thinktank December 5, 2009 15:31

[FLUENT]How to provide boundary conditions

I have a complex 3d geometry that I have to mesh and study the flow in. To start off, I am just trying to simulate poisuelle flow through a parallel plate channel. To start off, I made a cuboid in 3d in Soldworks, saved a drawing file as .dwg, and then imported it in ICEM. Then I converted the curves to a surface, and then used mesh type "quad" and mesh method "autoblock" to mesh the surface.

The mesh worked fine, and I was able to import the mesh to FLUENT. However when I imported the geometry from SOLIDWORKS I just got 4 curves and since these curves didnt have specific "parts" assigned to them, they didnt show up as separate entities in ICEM CFD as I would have liked it to be.

So my question is: how do I assign boundary conditions to a curve, which is not labelled as a separate part?

I have attached the .prj file as well as the mesh file for FLUENT below. It would be great if somebody could point out how the boundary conditions are assigned after importing a geometry from a CAD program, since I couldnt find anything on it in the documentation.


PSYMN December 6, 2009 09:58

All wrong?
I don't get why you are creating surfaces or importing geometry into Fluent...

Try some of the ICEM CFD Tutortials as a first go thru.

Your steps should have been more like...

1) create the solid 3D geometry in Solidworks and output as a dwg or acis or something like that. (ACIS is the best of the neutral formats)

2) Read the model into ICEM CFD. You should ALREADY have curves and surfaces and points... If you just have surfaces, run "Geometry (tab) => Build Diagnostic topology to build the rest." If you just have curves, you probably did something wrong in Solidworks.

3) Break up the model into parts such as Inlet, outlet, symmetry plane, etc. When the mesh is generated, the surface mesh (volume boundaries) will be in these parts and you will easily apply bocos in Fluent.

4) Set sizes and other meshing params with the mesh tab.

5) Mesh... You need a volume mesh for 3D Fluent. A quad mesh with the auto blocker is just a surface mesh and not at all appropriate for 3D Fluent (But great for structural explicit with LSDyna or something like that). Again, I will point you to the tutorials. You could make a nice Hexa mesh or a Tetra/Prism mesh.

6) Setup boco types (optional) and output mesh to Fluent...

7) Read mesh into Fluent and finish setting up, then run.

thinktank December 10, 2009 20:26

Hey Simon..thanks for your help...I didnt mean to import the geometry...i just meant importing the mesh...however thanks for your explanation. I will be a lot of help when I start the 3d modelling.

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