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-   -   CFX 5.7 rotational mesh deformation? (http://www.cfd-online.com/Forums/cfx/20694-cfx-5-7-rotational-mesh-deformation.html)

NymphadoraTonks October 7, 2004 17:19

CFX 5.7 rotational mesh deformation?
 
Hi all,

I've been playing with tut 20 ... the presure relief valve.

Can CFX 5.7 handle rotation of mesh cavities?

E.g. smaller cube cavity rotating within larger mesh cube?

In this case the geometric centre of the cavity would not translate but would rotate.

TIA

Glenn Horrocks October 7, 2004 18:11

Re: CFX 5.7 rotational mesh deformation?
 
Hi,

It sounds like you can describe your mesh with a stationary and a rotating mesh domains. Therefore you can model what you describe.

Glenn Horrocks

NymphadoraTonks October 8, 2004 04:11

Re: CFX 5.7 rotational mesh deformation?
 
Not quite ... I should have been a bit more specific.

The actual problem were an interested in is more akin to a high-aspect-ratio hexagonal cavity oscilating within a larger high-aspect-ratio hexagonal fluid domain.

I.e. complete rotation isn't possible and in fact we are only interested in a cyclically repeating partial rotation (~30*) not a 360* rotation.

TIA

NymphadoraTonks October 8, 2004 04:13

Re: CFX 5.7 rotational mesh deformation?
 
God ... need more coffee:

s/hexagonal/hexahedral

:)

NymphadoraTonks October 9, 2004 13:20

Re: CFX 5.7 rotational mesh deformation?
 
Hmmm ...

Unfortunately CEL specified mesh motion only allows for translational motion.

I'm busy investigating User Fortran spec'ed mesh motion as an alternative.

Glenn Horrocks October 10, 2004 18:24

Re: CFX 5.7 rotational mesh deformation?
 
Hi,

Don't forget you can do mesh deformation with CEL. If you can describe your motion with a CEL function this is often much easier to apply than fortran.

Glenn Horrocks

NymphadoraTonks October 11, 2004 04:36

Re: CFX 5.7 rotational mesh deformation?
 
You can specify *surface* motion with CEL with the volume mesh being automagically deformed as appropriate. (i.e. tut 20 A)

But as I understand it you cant explicity specify volume mesh deformation with CEL?

Or am I missing something?

Glenn Horrocks October 11, 2004 18:35

Re: CFX 5.7 rotational mesh deformation?
 
Hi,

Yes, you can explicitly define volume motion - as long as you can define the deformation at every node with a CEL function. You can also mix it up, for instance have a subdomain with the volume mesh explicitly defined and the remainder of the domain with the surface mesh defined and the remainder of the volume mesh determined by CFX using the Laplacian smoother.

Glenn Horrocks


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