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Old   October 12, 2006, 09:47
Default Mesh motion
  #1
jon
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Hi again all, Is it possible to apply a rotation to an object using the mesh deformation and the specified displacment? I can only see x,y,z components but i need to rotate my object?

any idas?
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Old   October 12, 2006, 11:23
Default Re: Mesh motion
  #2
Joe
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Of course it's possible, you just need to use the specified motions correctly.
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Old   October 12, 2006, 11:25
Default Re: Mesh motion
  #3
opaque
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Dear Jon,

Use CEL expressions for the x,y,z displacement components.. Those expressions would use the transformation from cylindrical components to cartesian components.

Then it should just work.

Good luck,

Opaque.

PS. You could also raise the issue with ANSYS CFX for an enhancement request.. Then, you would have to wait until ANSYS CFX 12.0..
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Old   October 12, 2006, 13:32
Default Re: Mesh motion
  #4
jon
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You lost me opaque! All I seem to be able to do is a transformation. COuld you explain a little further.

Thanks Jon
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Old   October 12, 2006, 13:49
Default Re: Mesh motion
  #5
opaque
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Dear Jon,

Your specified displacement must be a function of time as well. Otherwise, the displacement is a one shot transformation. You already saw that!!!

You can then control the angle of rotation at will.. For example, constant angular velocity, or variable angular velocity, or based on another metric such a total force on a blade.. It is up to you, basically.

Good luck,

Opaque
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Old   October 12, 2006, 14:05
Default Re: Mesh motion
  #6
jon
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Thanks for the speedy reply! I understand that and currently have a simple sin function to move my body and transform in the x,y,z coords.

I am currently doing it through pre using expressions. How can i model the rotation e.g. a door opening? I see nowhere to specify my rotation in the mesh motion fields?
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Old   October 12, 2006, 14:39
Default Re: Mesh motion
  #7
Robin
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Hi Jon,

You need to transform the rotation into the associated x, y, and z components. Simple trig.

Regards, Robin
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Old   October 12, 2006, 14:45
Default Re: Mesh motion *NM*
  #8
jon
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Old   October 13, 2006, 06:38
Default Re: Mesh motion *NM*
  #9
jon
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Old   October 13, 2006, 06:41
Default Re: Mesh motion
  #10
jon
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Firstly appologies for the blank threads, keep clicking wrong button!

I understand trig but that cannot help, using specified displacment in my mesh motion tab it is just going to tranform my shape and whatever i enter it will never rotate? There is no option for cylindrical coords.
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Old   October 15, 2006, 18:04
Default Re: Mesh motion
  #11
Glenn Horrocks
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Hi,

Make the mesh diaplacement transformation a function of the original node location, then each node gets a different transformation and you can model rotations and other arbitrary motions.

Glenn Horrocks
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Old   October 16, 2006, 10:00
Default Re: Mesh motion
  #12
jon
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Thanks everyone, greatly appreciated. I know have a rotating object. great stuff,

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