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Curved tube

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Franz Bozsak

Franz Bozsak

April 27, 2010 5:57pm UTC

Curved tube

Dear all,

I am trying to achieve a rather simple task and am unable to find a way to do it in COMSOL. I would like to draw a curved 3D tube (with angle alpha). This is a task I would usually expect to be solved by a command like extrude 2D shape along a predefined path, but I just can't find any command to do this. Has anyone ever tried this and found a way? Thank you so much for your help.

Franz

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Ivar Kjelberg

Ivar Kjelberg
Moderator

April 28, 2010 5:13am UTC in response to Franz Bozsak

Re: Curved tube

Hi

You have the 2D draw "extrude" and "revolve", for which you can "twist" and define an external rotation axis respectively, a simple illustration is given below. Start from a 2D and itwill create your 3D Geom at will

Have fun Comsoling
Ivar

Attachments:   GeomExtrRev.mph  

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Franz Bozsak

Franz Bozsak

April 28, 2010 8:05am UTC in response to Ivar Kjelberg

Re: Curved tube

Dear Ivan,

thank you for your response. I can't find where/hoqw to define an external axis for the revolution of extrusion.
Thank you.

Franz

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Ivar Kjelberg

Ivar Kjelberg
Moderator

April 28, 2010 8:41am UTC in response to Franz Bozsak

Re: Curved tube

Hi

you should see something like this, no ?

Ivar

Attachments:   Capture.JPG  

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Franz Bozsak

Franz Bozsak

April 28, 2010 8:50am UTC in response to Ivar Kjelberg

Re: Curved tube

Hi,

ahhh, now I understand what you mean by "external" axis. Of course, that is a possibility of doing this. Sorry, I just did not think about it that way. I was looking for something like the extrude along path thing. Ok, I see I can solve this particular problem like this, thankl you very much for pointing my head in the right direction; but what would I do if I need a more complex path? I mean do I have to basically split it into several tiny pieces and cunstruct it in this manner?
Thanks again,
Franz

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Ivar Kjelberg

Ivar Kjelberg
Moderator

April 28, 2010 9:41am UTC in response to Franz Bozsak

Re: Curved tube

Hi

Comsol internal CAD is rather basic, but still you can achieve fancy things, as you can use functions in several entries, or you need togo to matlab. Personally I mostly use the CAD interface with SolidWorks, eithr linked or via parasolid files

Have fun Comsoling
Ivar

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Tiaan Malherbe

Tiaan Malherbe

August 23, 2010 12:00pm UTC in response to Ivar Kjelberg

Re: Curved tube

Hi Ivar,

I wish to extrude a 3D tube along the trajectory defined by the points below. Each of the 12 points is defined by (x,y,z). How do I achieve this?

Thanks!

0.81 -2.36 1.32
0.86 -1.77 1.26
1.07 -1.59 1.06
1.28 -1.24 0.93
1.15 -0.27 0.84
0.97 0.21 1.02
0.68 0.51 1.09
0.31 0.74 1.26
-0.51 0.82 1.78
-0.83 0.63 2.04
-0.84 0.12 2.36
-0.69 -0.31 2.48

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Ivar Kjelberg

Ivar Kjelberg
Moderator

August 23, 2010 7:48pm UTC in response to Tiaan Malherbe

Re: Curved tube

Hi

you have a tricky question there. "My way" would be to make it as a spline axis in SolidWorks, but I'm sure it's possible in COMSOL too probably with some help from matlab, but I'm not sure what to propose there, certainly not in V4. Sorry cannot do better this time

--
Good luck
Ivar

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Tiaan Malherbe

Tiaan Malherbe

August 25, 2010 1:53pm UTC in response to Ivar Kjelberg

Re: Curved tube

Hi,

I have tackled the problem with assistance from Matlab! Thanks. I now encounter a problem when trying to intersect my tube with another geometry. I want to find the difference between the 2 but comsol comes up with the following error:

"Error_in_parameter_domain_topological_analysis"

Any idea on the cause?

Tiaan

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