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-   -   [GAMBIT] Rotating Circle in a parrallel plate (https://www.cfd-online.com/Forums/ansys-meshing/108319-rotating-circle-parrallel-plate.html)

 MrinalKR October 19, 2012 08:59

Rotating Circle in a parrallel plate

Hi friends

I want to rotate a circle(solid) inside a rectangular domain(fluid). what type of mesh have to create. I'm using gambit for meshing and solver fluent. Please help.:)

 -mAx- October 22, 2012 00:52

is it 2d?
will your circle rotate (moving mesh) or is it steady state problem?

 MrinalKR October 22, 2012 00:58

My problem is 2D and transient. Initially i want to rotate the circle then i have to implement translation motion also. Now i'm concentrating only on rotation.

 -mAx- October 22, 2012 01:18

*place your disk on its right position.
*split the rectangle with your disk
*copy the disk anywhere with a translation vector
*delete the initial disk (check with shaded mode that your rectangle has an hollow in place of the disk)
*define the circle edges (from rectangle) as interface
*define the circle edges (from copied disk) as interface
*move the copied disk with opposite translation vector back
*define the disk domain as fluid continuum
*mesh
*export
That's it for Gambit side

 MrinalKR October 22, 2012 01:44

Thank you..

 MrinalKR October 22, 2012 02:01

you told that "define the disk domain as fluid continuum".
Actually my rotating body is solid so i should be defined the disk domain as solid and the rectangular domain to be fluid?? is it correct??

 MrinalKR October 22, 2012 02:06

Can i use any type of meshing (structured or unstructured) for circular and rectangular domain ?

 -mAx- October 22, 2012 02:52

you can choose any kind of mesh, is it only your choice.
Ok then is your disk is solid, you are rightm you disk will appear as hollow since no NS-equations will be solved.
Than you can create a circle with greater radius than solid-disk, and split the rectangle.
And you do the same as previously explained but with an annulus

 MrinalKR October 22, 2012 03:14

Sorry..
i didn't understand what you have told may be because I'm new to moving mesh and FSI idea.

 -mAx- October 22, 2012 03:22

*place your disk on its right position.
*split the rectangle with your disk
*delete the initial disk (check with shaded mode that your rectangle has an hollow in place of the disk)
*create a circle with radius greater than solid-disk (create and move at right place)
*split the previous domain with the new circle (it will create an annulus around your solid disk which is hollowed)
*copy the annulus anywhere with a translation vector
*delete the annulus surface
*define the circle edges (from rectangle) as interface
*define the outer-circle edges (from copied annulus) as interface
*move the copied annulus with opposite translation vector back
*define the annulus domain as fluid continuum
*mesh
*export

 MrinalKR October 22, 2012 03:46

Thank you so much.. :-)

 MrinalKR October 22, 2012 03:51

Can we use boundary layer meshing instead of creating annulus region?? i have seen one tutorial of concentric cylinder rotating. In that they used boundary layer meshing. But i didnt get the complete tutorial. So i dont know for what purpose they have used.

 -mAx- October 22, 2012 03:56

you can also attach a BL on the inner-circle from annulus (this is par of meshing)

If you don't want to move you mesh (sliding mesh), then forget all points after "*delete the initial disk ".
And then you will have to set the circle as wall BUT with a velocity,
And off course you won't see you grid moving

 MrinalKR October 22, 2012 05:04

thank you very much for clearing the doubts and helping.. :-)

 rshbhb October 22, 2012 17:49

GAMBIT Geometry

1 Attachment(s)
Dear MAx,

Hello Sir/Ma'am.
I want to make the kind of geometry as shown in the image (attached) in the gambit software. I believe that you can help me.

Thank you.

 MrinalKR October 23, 2012 00:35

In my case the clearance between circle and walls of the rectangle is very less (.1 to .3mm). In this case how can i mesh??

 -mAx- October 23, 2012 01:23

Quote:
 Originally Posted by rshbhb (Post 387991) Dear MAx, Hello Sir/Ma'am. I want to make the kind of geometry as shown in the image (attached) in the gambit software. I believe that you can help me. Awaiting your reply soon. Thank you.

 -mAx- October 23, 2012 01:24

Quote:
 Originally Posted by MrinalKR (Post 388006) In my case the clearance between circle and walls of the rectangle is very less (.1 to .3mm). In this case how can i mesh??
Post a picture

 MrinalKR October 23, 2012 01:29

1 Attachment(s)