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

hectordiaz · May 11, 2011, 06:54

Hello,

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,

Héctor.

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

jeevankumarb · May 11, 2011, 08:55

Hello,

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.

Regards
jeevan

jeevankumarb · May 11, 2011, 08:57

sorry forgot to attach the image

hectordiaz · May 11, 2011, 09:07

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, 09:23

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

hectordiaz · May 11, 2011, 09:28

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, 09:37

Then how did you create the mesh?

jeevankumarb · May 11, 2011, 09:38

is it unstructured mesh?

hectordiaz · May 11, 2011, 09:42

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, 09:45

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, 09:47

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

hectordiaz · May 11, 2011, 09:56

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.

Regards,

Héctor.

hectordiaz · May 13, 2011, 05:38

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.

Regards.

jeevankumarb · May 13, 2011, 06:45

Helo Diaz,

you made a good blocking but here were few problems, i made some changes in the blocking and uploaded at below location.
http://www.2shared.com/file/zTLvBEIM/modified_mesh.html.

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

Regards

hectordiaz · May 13, 2011, 06:57

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, 07:30

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, 07:36

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.

May 11, 2011, 06:54	Problem with meshing (uncovered faces, can't export bocos)	#1
hectordiaz New Member Hector Diaz Join Date: May 2011 Posts: 17 Rep Power: 15	Hello, 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, Héctor. PS: As the forum does not let me to attach .rar files I uploaded it here.

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May 11, 2011, 08:55		#2
jeevankumarb Member jeevan kumar Join Date: Mar 2009 Posts: 88 Rep Power: 17	Hello, 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. Regards jeevan

May 11, 2011, 09:07		#4
hectordiaz New Member Hector Diaz Join Date: May 2011 Posts: 17 Rep Power: 15	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.

May 11, 2011, 09:23		#5
jeevankumarb Member jeevan kumar Join Date: Mar 2009 Posts: 88 Rep Power: 17	can you upload your blocking file, i will do the modifications and seny you.

May 11, 2011, 09:28		#6
hectordiaz New Member Hector Diaz Join Date: May 2011 Posts: 17 Rep Power: 15	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).

May 11, 2011, 09:37		#7
jeevankumarb Member jeevan kumar Join Date: Mar 2009 Posts: 88 Rep Power: 17	Then how did you create the mesh?

May 11, 2011, 09:38		#8
jeevankumarb Member jeevan kumar Join Date: Mar 2009 Posts: 88 Rep Power: 17	is it unstructured mesh?

May 11, 2011, 09:42		#9
hectordiaz New Member Hector Diaz Join Date: May 2011 Posts: 17 Rep Power: 15	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.

May 11, 2011, 09:45		#10
jeevankumarb Member jeevan kumar Join Date: Mar 2009 Posts: 88 Rep Power: 17	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.

May 11, 2011, 09:47		#11
jeevankumarb Member jeevan kumar Join Date: Mar 2009 Posts: 88 Rep Power: 17	Try to do some tutorial Hexa blocking you will understand how simple and user friendly the tool is.

May 11, 2011, 09:56		#12
hectordiaz New Member Hector Diaz Join Date: May 2011 Posts: 17 Rep Power: 15	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. Regards, Héctor.

May 13, 2011, 05:38		#13
hectordiaz New Member Hector Diaz Join Date: May 2011 Posts: 17 Rep Power: 15	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. Regards.

May 13, 2011, 06:45		#14
jeevankumarb Member jeevan kumar Join Date: Mar 2009 Posts: 88 Rep Power: 17	Helo Diaz, you made a good blocking but here were few problems, i made some changes in the blocking and uploaded at below location. http://www.2shared.com/file/zTLvBEIM/modified_mesh.html. There are single edges but it is no issue since your model is a 2D, and single edges are quite common with 2D mesh. Regards

May 13, 2011, 06:57		#15
hectordiaz New Member Hector Diaz Join Date: May 2011 Posts: 17 Rep Power: 15	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.

May 13, 2011, 07:30		#16
jeevankumarb Member jeevan kumar Join Date: Mar 2009 Posts: 88 Rep Power: 17	sorry i didnt get you what you realy ment, can you make it little clear may be few images will do good.

May 13, 2011, 07:36		#17
hectordiaz New Member Hector Diaz Join Date: May 2011 Posts: 17 Rep Power: 15	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.