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-   -   [GAMBIT] 3D pipe o-grid GAMBIT (http://www.cfd-online.com/Forums/ansys-meshing/90862-3d-pipe-o-grid-gambit.html)

salzferkel July 22, 2011 07:31

3D pipe o-grid GAMBIT
 
Hi,

i've try to make o-grid circular mesh on pipe 3-d. tried many times since yesterday didn't work.


now my idea, i make a face circle, and i have to split it into 8 pieces each @45

how to split the circle face into 8 pieces faces @45

how to do this on gambit ??

many thanks for help.
salzferkel

-mAx- July 22, 2011 07:50

post a sketch of what you want

salzferkel July 22, 2011 07:52

1 Attachment(s)
Quote:

Originally Posted by -mAx- (Post 317084)
post a sketch of what you want

thanks max.

here the pic

regards

-mAx- July 22, 2011 08:01

1 Attachment(s)
on your picture you have a coax cylinder (one small cylinder hollow)
Attachment 8518

salzferkel July 22, 2011 08:13

1 Attachment(s)
Quote:

Originally Posted by -mAx- (Post 317089)
on your picture you have a coax cylinder (one small cylinder hollow)
Attachment 8518

hi max,

yeahhh this is my problem.

i can make the one that in the middle hollow. i creat the mapped mesh on the outer face of cylinder, then submapped mesh on the face, circle ( inlet ) afterthat then i say to gambit should make the whole pipe (volume meshing) .. i've got as attached. it looks not good as in the hollow

should i just leave it hollow for the computation ? because it should a full cylinder.

attached the one i did now

-mAx- July 22, 2011 08:24

1 Attachment(s)
Instead of a circle in the middle, create a square, then split the surface which surrounds the square into 4 sub-surfaces (see picture).
Mesh the square first, then the other.
Attachment 8520

salzferkel July 22, 2011 08:40

1 Attachment(s)
Quote:

Originally Posted by -mAx- (Post 317095)
Instead of a circle in the middle, create a square, then split the surface which surrounds the square into 4 sub-surfaces (see picture).
Mesh the square first, then the other.
Attachment 8520


alright, how can i split the surface that surrounds the square into 4 sub-surfaces in gambit ?

thanks

-mAx- July 22, 2011 08:43

create your vertex on the circle (with split edge for instance)
Then split surface with vertex: select one square corner and the appropriate vertex on the circle (it will split the surface with a line)
etc..

salzferkel July 22, 2011 09:32

2 Attachment(s)
Quote:

Originally Posted by -mAx- (Post 317102)
create your vertex on the circle (with split edge for instance)
Then split surface with vertex: select one square corner and the appropriate vertex on the circle (it will split the surface with a line)
etc..


thanks a lot max.

i've splitted the surface and the square as order.

now i try to mesh, if i starting from the surface square as map, then the surface circle ( see attached) gambit offer only pave option. i mean, if i switch to map mesh, it didn't work.

if i starting meshing from surface of the contour of the cylinder, then the the (inlet ) splitted surface (circle and square)
i got the mesh not as circular. see attached pic 2.

im sorry, im quite new with gambit.

thanks lot :)

-mAx- July 22, 2011 09:41

split also volumes:
split full pipe, with square-section-pipe
Then split volume surrounding the square-section-pipe with planes which will generate 4 sub-volumes.

salzferkel July 22, 2011 11:12

1 Attachment(s)
Quote:

Originally Posted by -mAx- (Post 317110)
split also volumes:
split full pipe, with square-section-pipe
Then split volume surrounding the square-section-pipe with planes which will generate 4 sub-volumes.


thanks lot max.

but i got problem with splitting the volumen. it didint work. gambit said, it has a non volumen geometry. i try to comprehend.

i created 4 vertex alongside surface circle. then split surface with the square.

i found when i splitted the surface circle with the square with vertices ---> virtuell. (see attached) and the face change to non geometrical face. it means virtuelle surface ?? not real geometry

i dont know what i did wrong with splitting.

salzferkel July 22, 2011 14:23

3 Attachment(s)
Hi Max...

finally i find the way!

well i get your idea to split the surface. but seems when i the circle edge splitted , seems the circle has got distorsion ,and the end of the vertex to another part of the surface didnt joint together.

now i didnt create the square in the middle. i just make the circle surface. then spitted into 4 quadrant.

when i click the mesh on the face, it marked a pizza slice orthogonal.

i've got not much experience, but i think the meshing now quiet good for computing. see attached.
what do you think ? is that enough to a good circular meshing for computing ?

thanks lot for helping.

:)

finally i know how to split the surface. so now i made the version square with circle. (see attached) it also works.

many thanks Max!

desert_1250 July 24, 2011 01:54

extrude in Gambit
 
can any body tell me :
how can i extrude airfoil in Z dir by using GAMBIT?

tanx
___________
rasoul

-mAx- July 25, 2011 09:48

Quote:

Originally Posted by desert_1250 (Post 317241)
can any body tell me :
how can i extrude airfoil in Z dir by using GAMBIT?

tanx
___________
rasoul

sweep surfaces, and choose vector option

-mAx- July 25, 2011 09:51

Quote:

Originally Posted by salzferkel (Post 317147)
what do you think ? is that enough to a good circular meshing for computing ?

There is no only one way to mesh a domain.
You can mesh with hexa, tetra, wedge, hybrid, coarse, fine, etc...

desert_1250 July 25, 2011 10:19

tanx max for your quick reply, i will try it ASAP, but would you tell me how can i see velocity or pressure contour for inside of the 3d geometry. on the othe hand i wanna eliminate or pale all bondaries to see what happen in it after run and see any contours. i dont want to use clip or slice or etc

tanx
___________
Rasoul

-mAx- July 25, 2011 10:54

if you don't want to use clip, sweep etc... then there are path lines.

desert_1250 July 25, 2011 23:47

how to get path line!!!?

____________
Rasoul

-mAx- July 26, 2011 03:37

Quote:

Originally Posted by desert_1250 (Post 317478)
how to get path line!!!?

____________
Rasoul

http://my.fit.edu/itresources/manual...tg/node357.htm

desert_1250 July 26, 2011 04:15

tanx but i use OpenFOAM software not Fluent, how did it in OpenFOAM??

_______
Rasoul


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