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-   -   [GAMBIT] meshing 3-D flat tube (http://www.cfd-online.com/Forums/ansys-meshing/110364-meshing-3-d-flat-tube.html)

vrk December 9, 2012 22:14

meshing 3-D flat tube
 
4 Attachment(s)
Hello, I am trying to mesh a 3-D flat tube ( rectangular pipe with two semi-circular ends, please see fig. 1). I created and meshed the geometry in the following procedure:
1. created the inlet face1 (by creating vertices, please see fig. 2)
2. swept the face in Z-direction to create volume 1
3. created virtual edge on inlet face by joining vertices 3 & 4 and similarly on outlet face as well.
4. created virtual faces at inlet and outlet by joining the edges (please see fig. 3)
5. created virtual volumes by stitching faces ( please see fig. 4).
6.created edge nodes and meshed the virtual volumes individually.

I followed the above procedure so that i can get fine mesh near the upper and curved wall.

While specifying boundary conditions, I have to select two virtual faces (rectangular and quarter circle face) to give inlet and outlet B.C's.If i select face1 as inlet, fluent is not recognizing any mesh on it.

Is this the correct procedure for creating the mesh for this geometry?
Any help in meshing this geometry would be highly appreciated.

Thanks,
Ravi

-mAx- December 10, 2012 03:54

are you able to display your whole geometry (mesh) in fluent?
Question is if gambit exports all your volumes.
PS: I am pretty sur you have skewed cells in your face.2 , especially in neighborhood from upper edge (common with face.1)

Far December 10, 2012 07:00

use triprimitve scheme for the corner faces and then volume> Hex > cooper

Far December 10, 2012 07:46

4 Attachment(s)
see this please. You need to implement the similar topology either by decomposition or using triprimitive scheme.

vrk December 10, 2012 17:16

2 Attachment(s)
mAx,
Thank you very much for your reply. When i try to export the mesh in Gambit, it is giving me the warning sign "Volume. 1 is not meshed and is not exported". Also boundary conditions on Face. 1(velocity Inlet) and Face. 4 (Outflow) are not exported. Also in "Fluent-Boundary conditions", I can't see velocity Inlet and outflow b.c's. Please see Fig. 1 for the warning sign given by Gambit in Transcript window. In Fig. 2, I assigned the velocity inlet and out flow B.C.'s on both virtual faces (rectangular and quarter circle). I am not sure if this is the right procedure or not?
Is there any other way to mesh the geometry without creating virtual volumes and also i need to have a finer and smoother mesh near wall boundaries?

Thanks
Ravi

vrk December 10, 2012 17:29

Far,
Many thanks for your reply with attached figures. Did you mesh the face with out splitting it? or did you split the face into rectangular face and quarter circle face and then meshed them separately?
Could you please tell me in detail how you created the geometry and meshed it.

Thank you.
Ravi

Far December 10, 2012 23:57

I did meshing in ICEM and for just reference I post pics. Definitely if you want hexa meshing then you need to split the face into regular rectangular and quarter face (not necessarily the different volumes).

Here is the procedure for the Gambit ......
Case one : One volume and two faces.

Mesh that face with map and triprimitve mesh and then apply the volume meshing with option Hex+cooper.

Case II : Two volume and naturally two faces on both ends

Mesh rectangular face with normal map and hexa meshing methods
Mesh quarter volume by first meshing the quarter face using the triprimitive and side faces with map meshing and then volume meshing using Hexa + cooper scheme.

-mAx- December 11, 2012 02:21

Quote:

Originally Posted by vrk (Post 396780)
mAx,
Thank you very much for your reply. When i try to export the mesh in Gambit, it is giving me the warning sign "Volume. 1 is not meshed and is not exported". Also boundary conditions on Face. 1(velocity Inlet) and Face. 4 (Outflow) are not exported. Also in "Fluent-Boundary conditions", I can't see velocity Inlet and outflow b.c's. Please see Fig. 1 for the warning sign given by Gambit in Transcript window. In Fig. 2, I assigned the velocity inlet and out flow B.C.'s on both virtual faces (rectangular and quarter circle). I am not sure if this is the right procedure or not?
Is there any other way to mesh the geometry without creating virtual volumes and also i need to have a finer and smoother mesh near wall boundaries?

Thanks
Ravi

It doesn't make any difference if you export a real or virtual meshed-volume.
In your case you need to know why the volume isn t exported.
For sure Gambit gives you some info while you attempt to mesh it

vrk February 8, 2013 16:45

Far,

Could you please tell me how you meshed the 3-D falt tube geometry in ICEM CFD?I am new to this software as i started using it very recently. I really appreciate if you could tell how you did meshing in ICEM.

Thank you.
Regards,
Ravi

Far February 9, 2013 04:57

Hey it was really simple. Did you check the files?

vrk February 17, 2013 19:10

2 Attachment(s)
Far,

I tried to mesh the Flat tube geometry in ICEM CFD. But, I am unable to specify nodes along the z-direction edges.Can you tell me where i am doing wrong.

Thanks for your help.

Ravi

Far February 18, 2013 13:49

1 Attachment(s)
Please see this ...

aalisha August 26, 2014 03:04

Mesh not written and is not exported
 
Quote:

Originally Posted by vrk (Post 396780)
mAx,
Thank you very much for your reply. When i try to export the mesh in Gambit, it is giving me the warning sign "Volume. 1 is not meshed and is not exported". Also boundary conditions on Face. 1(velocity Inlet) and Face. 4 (Outflow) are not exported. Also in "Fluent-Boundary conditions", I can't see velocity Inlet and outflow b.c's. Please see Fig. 1 for the warning sign given by Gambit in Transcript window. In Fig. 2, I assigned the velocity inlet and out flow B.C.'s on both virtual faces (rectangular and quarter circle). I am not sure if this is the right procedure or not?
Is there any other way to mesh the geometry without creating virtual volumes and also i need to have a finer and smoother mesh near wall boundaries?

Thanks
Ravi

Hey Ravi,

I know its a very old post but I am also struggling with something similar. I am working on a straight blade collapsible turbine. while generating the mesh I also get this error of mesh not written on face (interface between the stator and rotor) and is not exported. Do you know why this error is occurring again and again? If you can suggest it will be a great help.

Thanks-
Aalisha


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