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October 31, 2012, 03:54 
Non Sweepable bodies

#1 
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Shuvayan Brahmachary
Join Date: Oct 2012
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Hi everyone.
I am working on a geometry where I have a cube and inside of which there is a sphere (Cut material, i.e the sphere is hollow). Now the problem stands that i can't create the sweepable bodies (at least in the part where the cube has the sphere in it, but I can create the sweepable area outside the sphere). I need to create sewwpable bodies for the antire cube (minus the hollow sphere). any suggestion??? Sphere inside a cube sliced in three planes mutually perpendicular.JPG no sweepable bidoes.JPG no sweepable biodies 2.JPG 

October 31, 2012, 08:34 

#2 
Senior Member

The bodies you create are not sweepable because of the sphere you put in the center. I assume you have DesignModeler, so if you want to get a mesh like in the images below you need to split the geometry to help the mesher.
This is meshed with the Multizone method and will result in the same kind of mesh that you get in ICEM hexa. I have also attached the project file where the mesh is created. Hope it helps. https://www.dropbox.com/s/7oo40wpif7...be_sphere.wbpz 

October 31, 2012, 09:15 

#3 
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Shuvayan Brahmachary
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Thanks a lot man.. you are a real jem. It was the thing I have been trying for days now and thanks to you I finally have the solution.
Really appreciate it. Thanks again 

October 31, 2012, 09:26 

#4 
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Shuvayan Brahmachary
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While working on your project file...I couldn't view the mesh like you showed in your second picture. What could be the possible reason??
thanks in advance 

October 31, 2012, 09:31 

#5 
Senior Member

Select one of the bodies, right click and choose "hide body"


October 31, 2012, 10:33 

#6 
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Shuvayan Brahmachary
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Thanks that worked out. But This is the new issue I am getting. Tetrahedron mesh in the inner sphere. DO you know the possible cause?? I want it hexahedron like you did.
The pic. is attached here tetrahedron mesh for sphere but why.JPG 

October 31, 2012, 10:39 

#7 
Senior Member

Did you get that with my file?


October 31, 2012, 11:52 

#8 
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Shuvayan Brahmachary
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No yours file was just fine. I just followed your steps and made one by my own. I must have done some mistake. I'll go through it once more. But Thanks for the help.


November 1, 2012, 05:15 

#9 
Senior Member

Do youactually have a sphere body in there btw? If that's the case, just delete it


November 1, 2012, 06:31 

#10 
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Shuvayan Brahmachary
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Okay. you mean to say i have to add the sphere like you did BUT slice material right??


November 1, 2012, 06:36 

#11 
Senior Member

Just saying that if you want to model flow around the sphere, you only need the wall, not the actual sphere. So yeah, slice the cube with the sphere but then delete or supress the sphere body when meshing. Not sure if that's your problem, but from your image it looks like you have a nice mesh around the sphere and then the sphere itself is meshed seperately with tet mesh. But maybe the image is fooling me


November 1, 2012, 07:55 

#12 
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Shuvayan Brahmachary
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Alright...Let em explain my problem that I am trying to solve. I need a solid CUBE with a Hole (SPHERE). There will be an inlet (any face of cube) and outlet (opposite face of the cube) and in between there will be this sphere (as a hole). I was told to get very very fine mesh indeed (like you created the inflated layer) near the sphere wall (all Hex, none Tet)for studying the velocity profile.
I'm attaching few pictures clear the confusion. Can you help Please?? comparasion mine Vs. yours.JPG non sweepable sphere.JPG 

November 1, 2012, 08:00 

#13 
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Shuvayan Brahmachary
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Your suggestion worked. I just deleted the internal sphere and its sweepable now. Thanks a lott


November 1, 2012, 08:02 

#14 
Senior Member

Either use my files and just alter the dimensions in designmodeler (you would need a bigger cube if that is supposed to be your entire fluid domain, since the sphere is relatively big. Will help get accurate reults in the simulation), or select all bodies except the 6 bodies surrounding the sphere, and surpress them.
Then you are left with a multibody part consisting of only these 6 bodies. The inner boundaries of these bodies will then represent the sphere. EDIT: Ok good, no problem 

December 16, 2012, 13:27 

#15 
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Shuvayan Brahmachary
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Hi there!.
I owe a lot to you for the kind of help you have been. I was wondering if you could give me some suggestion for this problem which I have tried many times but it returns an error 255. The geometry is same except that instead of a spherical hole inside I have a triangular hole with two flaps. I need to create structural mesh and I was able to do so by creating slices and multizone meshing but it shows error 255 at solver manager. Can you provide any suggestions? I am badly stuck for days. Last edited by b.shuvayan; December 17, 2012 at 06:51. 

December 19, 2012, 11:12 

#16  
Senior Member

Quote:


December 23, 2012, 14:56 

#17 
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Shuvayan Brahmachary
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HI.
The previous problem solver absoultely perfectly, in which you helped a lot. But I am trying this new problem where everything is same, even the boundary conditions. But the difference lies in the fact that the spherical hole has been replaced with triangular hole ( of certain width ) and it has flaps on either side of the triangle as well. The triangle is situated at the centre of the solid cube and I need to model flow around the triangle. I tried your method of multi zone meshing but dur to unsymmetric geometry (i.e the triangle, unlike sphere), I am not able to to do fine mesh (hehxa hedral elements), like you did in the previous problem (images available above). So I want to know if there is a way to get hexahedral mesh by any other way for unsymmetrical bodies like this one?? thanks in advance :) 

December 23, 2012, 15:03 

#18 
Senior Member

Seems like quite a big change from the previous geometry (sphere). Can you share an image of the geometry?


December 24, 2012, 14:24 

#19 
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Shuvayan Brahmachary
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December 26, 2012, 03:55 

#20 
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Shuvayan Brahmachary
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Hi there!
I am sending a JPEG format picture for the clear view of the geometry. Hope it helps :) Thanks in advance 

Tags 
ansys meshing, cfx, sweep 
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