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hectordiaz May 11, 2011 05:54

Problem with meshing (uncovered faces, can't export bocos)

I have been trying to fix this problem and it is driving me crazy. I just can not fix it, no matter what I do. For sure I am doing something wrong, but I do not find what as I am a rookie with this software.

My problem basically is to mesh the geometry (see attached file) and then exporting to fluent to have all the defined parts (the ones with proper names, like walls, inlets or outlet) with their proper boundary condition so I can enter in Fluent and set them.

The geometry is not complicated and I know I have to be doing something wrong (maybe many things) but I just can not find the solution. I read many threads in this forum but nothing worked. I tried to associete the mesh to elements and does not work as well.

I would much appreciate some help or guidance about how to fix it and start working with Fluent which is the most important thing about my project.

Thanks in advance,


PS: As the forum does not let me to attach .rar files I uploaded it here.

jeevankumarb May 11, 2011 07:55


The problem is that you have non-confermal mesh. moslty you have created 3 saperate blocks and didnt merge the blocks. which is leading to uncovered faces, see image attached. Try to merge the corner vertices at the three location or make the mesh by single blocking and then splitting to fit your geometry.

Your mesh also has single edges mostly you have not properly associated the edges to the curves. Associate all the boundry edges to corrosponding curves.


jeevankumarb May 11, 2011 07:57

1 Attachment(s)
sorry forgot to attach the image:)

hectordiaz May 11, 2011 08:07

Although I do understand what you mean I do not know how to do it. To create the mesh I really need to split the surfaces if I want to do it with All Quad.

Also, there is still the problem to associate all the walls to the mesh which I am incapable of. :(

I really appreciate your help. ICEM is being a nightmare lately.

jeevankumarb May 11, 2011 08:23

can you upload your blocking file, i will do the modifications and seny you.

hectordiaz May 11, 2011 08:28

This is going to sound like the "Stupid comment of the day" but I have no block file as I do not use the blocking tool (and I am starting to suspect that this is the source of the problems).

jeevankumarb May 11, 2011 08:37

Then how did you create the mesh?

jeevankumarb May 11, 2011 08:38

is it unstructured mesh?

hectordiaz May 11, 2011 08:42

I created the geometry, then the surfaces and then I meshed the surfaces and the curves.

I think it is an unstructured mesh, but I am not familiar with these concepts.

Sorry about my ineptitude, I have not much experience with this software.

jeevankumarb May 11, 2011 08:45

sorry. i didnt notice this, you have used Autoblock mesh.
in the compute surface mesh part rather then selecting from screen try to mesh with all.

when i did this i didnt get any uncovered surfaces.
the best thing for you will be go for a blocking aproach u will have a better control and wont face much dufficulties since your geom is relatively simple.

jeevankumarb May 11, 2011 08:47

Try to do some tutorial Hexa blocking you will understand how simple and user friendly the tool is.

hectordiaz May 11, 2011 08:56

I will do then. But I do not know if the problems regarding the curves associated to lines would be fixed.

I will post any advances I achieve by doing block meshing.

Again, thanks a lot.



hectordiaz May 13, 2011 04:38

Hello again,

I finally used the blocking meshing and now it is looking a little better but I am still having problems with the bocos and internal walls. I have attached al the project including the blocking file.


jeevankumarb May 13, 2011 05:45

Helo Diaz,

you made a good blocking but here were few problems, i made some changes in the blocking and uploaded at below location.

There are single edges but it is no issue since your model is a 2D, and single edges are quite common with 2D mesh.


hectordiaz May 13, 2011 05:57

It looks really great, thanks a lot.

Now I am facing other problem, which is associate the parts I have defined to the mesh so they appear on fluent as boundary conditions. I am doing it now but they do not appear or just parts of them. Any suggestions?

Again, thanks a LOT.

jeevankumarb May 13, 2011 06:30

sorry i didnt get you what you realy ment, can you make it little clear may be few images will do good.

hectordiaz May 13, 2011 06:36

Do not worry, I fixed it on my own, although I still have to test the mesh in Fluent.

What I meant was that I need to associate some parts (for example those named Inlet1, Inlet2...) to the mesh and give them a boundary condition. This way Fluent will know that it has to use a boundary condition. If those parts are not properly associated I can not use them in fluent.

Again, I owe you big time. Thanks a lot.

PS Creating this mesh properly is very important to me because is for my Master Thesis and to do the simulations in Fluent I need it to be the best possible. :)

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