Flow simulation using CFX

[BoB_from_jungle]

Hi everyone!
I go on trying to solve my task about permeability.
I found this information http://texgen.sourceforge.net/workshop/ ... alysis.pdf (page 10) how I can find the permeability by CFX ansys and I have a lot of problem with it.

1. I exported volume mesh from Texgen (it's in attachement) and parameters of mesh as the same as on the page 11.
2. I edited mesh in CFX as it says on page 13
3. and then I have to define the fluid domain for the gaps between yarns only. But I just have a mesh in the yarn, without mesh in the free space (gap). I figure the yarn have to be empty, there is not mesh in yarn. how can I fix this problem?

Here http://texgen.sourceforge.net/index.php ... olume_Mesh wrote I can create volume mesh of yarn, matrix and both. "this option creates a tetrahedral mesh of the yarns, matrix or both"

[louisepb]

Hi,

I think that there is maybe some confusion about the terminology here. The model that you show includes both the yarn and matrix. The yarn 'gaps' referred to on page 14 of the tutorial are the matrix part of the mesh which you should be able to select.

I will correct the user guide - the volume mesh automatically creates a mesh for the whole domain, both yarns and matrix.

Hope that helps,
Louise

[BoB_from_jungle]

louisepb, thank you for your answer.

What's the matrix? I suppose matrix is the part of polymer composite, right?

[louisepb]

Hi,

The matrix is the part in which the yarns are embedded, typically some sort of resin for polymer composites.

Best regards,
Louise

[BoB_from_jungle]

Dear louisepb,

How can I Defining domains in CFX?

[louisepb]

Hi,
I'm afraid I'm not a CFX user myself ( the tutorial was written by a colleague) but the page on the tutorial says to use 'Insert->Domain'. Failing that I can only suggest looking in the CFX user manual.

Best regards,
Louise

[BoB_from_jungle]

To solve the problem, I have to pick just matrix out, but in my model I can pick all model out for some reason.

[louisepb]

Hi,
Apparently if you pick the whole face you should then be able to disable the yarn areas.

Best regards,
Louise

[BoB_from_jungle]

Hi,
Apparently if you pick the whole face you should then be able to disable the yarn areas.

Best regards,
Louise

I can't disable the yarn areas, I don't know why. I'm not good at Ansys.


Next picture about how I try to define fluid domain, I've already had Default domain, but I have to create new one. And then I should choose the location of this domain (between Domain and 7 yarns)


If I choose domain I get the mesh of whole part (Unit cell: yarn and matrix)

There isn't problem to create unit cell in some CAD, but I can't use CFXImportVTK.exe because my file has the different extension (no .vtu)

[louisepb]

Hi,
If you use TexGen to export your volume mesh you can select a .vtu file type using the 'Save as type' dropdown when you select the filename. You should then be able to use the CFXImportVTK.exe. Hopefully you should then be able to select the appropriate parts of the model.

Hope that helps,
Louise