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[GAMBIT] Problem with scale

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Old   September 25, 2013, 01:34
Default Problem with scale
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Hi.
I am creating the model in autocad or solidworks with my dimensions. After exporting that in .sat or .igs file and importing that into autocad or solidworks or gambit, i see the dimensions are very large. I am scaling that file in autocad or solidworks but the model is going to mixed. How can decrease dimensions in gambit?
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Old   September 25, 2013, 01:45
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gambit has no unity system.
You wil have to scale your model in your solver
For instance, I am using ProE with all dimensions in mm.
As I said Gambit imports the geometry without unity and all dimensions are in [-]
Then I have to scale my mesh in the solver ( x 0.001)
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Old   September 25, 2013, 02:22
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Quote:
Originally Posted by -mAx- View Post
gambit has no unity system.
You wil have to scale your model in your solver
For instance, I am using ProE with all dimensions in mm.
As I said Gambit imports the geometry without unity and all dimensions are in [-]
Then I have to scale my mesh in the solver ( x 0.001)
Thanks. I could to decrease my dimensions before exporting but after importing the .sat file into Gambit, the nodes are not connect to edges. I think this can produce problem later. The spacing between nodes are 0.3 cm. Please see attached image.
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Old   September 25, 2013, 02:25
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ah ok, then forgot what I said.
It sounds like tolerance issue while importing
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Old   September 25, 2013, 02:34
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In creating the volume, gambit says: "Can not create ACIS body, Is this an open shell?"
How can i fix that? I can not create this geometry into the gambit because it is complicate.
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Old   September 25, 2013, 02:37
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are you importing a volume or only surfaces (and in which format? igs, step, sat?)
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Old   September 25, 2013, 02:38
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I am importing the surfaces in .sat format.
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Old   September 25, 2013, 03:14
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check if you can close your volume with all your surfaces (regarding the message you get, one surface is missing for closing the volume)
It could be also a connectivity problem
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Old   September 25, 2013, 03:20
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Can i import that to gambit in mm (large geometry) and after meshing and importing mesh into fluent, scaling that?
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Old   September 25, 2013, 03:25
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yes you can (again, Gambit doesn't provide unity)
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Old   September 25, 2013, 03:33
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Quote:
Originally Posted by -mAx- View Post
yes you can (again, Gambit doesn't provide unity)
So if i import large geometry to gambit, i should use large interval size to meshing that? For example in small model (m) i am using 0.02 for interval size, after increasing the size in mm, i should use 20 for interval size?
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Old   September 25, 2013, 03:50
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why do you want to increase sizes?
Just import your geometry
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Old   September 25, 2013, 03:53
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You saw (in post 3), in small size, the nodes can not connect to edges but in large size they are connect after importing and i can create volume.
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Old   September 25, 2013, 04:02
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should be tolerance issue.
Don't you have tolerance option while importing?

What are dimensions of your large model, and small model?
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Old   September 25, 2013, 04:08
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I don't have any tolerance option. My model length is 6 meters. I have size option for exporting in solidworks 2013. With choosing mm, the model is going to mm and it is large (6000 in gambit) and with choosing meter, the model is going to meter and it is small (6 in gambit) but i have problem with that.
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Old   September 25, 2013, 04:17
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then choose mm (large model)
Mesh your model, then you will have to scale your mesh in your solver, else solver will undersstand 6000m (by scaling, solver will multiply all your dimensions with factor 0.001)
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Old   September 25, 2013, 04:23
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Thank you so much. Please see post 11. Is that right?
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Old   September 25, 2013, 04:27
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then yes
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