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-   -   BOUNDARY LAYER MESH (http://www.cfd-online.com/Forums/fluent/49979-boundary-layer-mesh.html)

Kostas Pan December 5, 2008 03:47

BOUNDARY LAYER MESH
 
I have made a surface in gambit and i want to make a "boundary layer" near at one edge. I make the boundary layer with a tool "create boundary layer". But the remainder surface of this surface how i fill it with mesh??

zongtwi December 5, 2008 04:12

Re: BOUNDARY LAYER MESH
 
Just mesh it like you normally would, using create surface mesh.

Hope that helps.

Kostas Pan December 5, 2008 06:22

Re: BOUNDARY LAYER MESH
 
Yes, i do this but it make a mesh over the boundary mesh...

Thus, appear two mesh (the boundary mesh and the mesh from cretion surface mesh)one over other...


zongtwi December 5, 2008 07:45

Re: BOUNDARY LAYER MESH
 
Then you must have done something wrong...the mesh should not overlap.

In the GAMBIT documentation, there are a number of tutorials that teaches you how to do that. Try that out.

Hope that helps.

Kostas Pan December 6, 2008 03:43

Re: BOUNDARY LAYER MESH
 
Thanks...ok

kostas December 6, 2008 17:20

Re: BOUNDARY LAYER MESH
 
I do the boundary layer and after i try to fill all surface with mesh. For mesh of remender surface i use Sheme: map , Quad.

Now the mesh stick up the boundary mesh but at some points the mesh it wrong as well as look the above picture which i sent.

http://www.users.otenet.gr/~meenseto/p1j.jpg http://www.users.otenet.gr/~meenseto/p2j.jpg

what i do???

thanks...

mahi December 8, 2008 06:52

Re: BOUNDARY LAYER MESH
 
Is it a planar surface? Looks like you have meshed the other edges first. Remove the edge meshes in all the other edges, put the boundary layer at the required edge, then mesh the remaining edges. Now it should be meshable fine.

kostas December 8, 2008 13:06

Re: BOUNDARY LAYER MESH
 
Yes, first i make the boundary layer and after i put the nodes at other edges. What you mean with planar surface?


mahi December 9, 2008 00:33

Re: BOUNDARY LAYER MESH
 
OK in that case you might have given a coarse mesh on the other edges. Please do one thing, use the ratio option on the other edges and check if it make any difference. Or else you can split the other edges and have a transition from fine to coarse mesh

kostas December 9, 2008 08:16

Re: BOUNDARY LAYER MESH
 
Can you tell me the all steps?

I do these but i dont understant. How operete the boundary layer? First you must make the boundary layer and after a procedure for other nodes?

When i make the boundary layer and make the other nodes at other-near edge and after split the nodes at two mesh, the boundary layer dissapear.

mahi December 9, 2008 09:09

Re: BOUNDARY LAYER MESH
 
Hi, can you put a picture of the surface alone here? I want to see it without the boundary layer.

kostas December 9, 2008 13:56

Re: BOUNDARY LAYER MESH
 
Is the right surface which has not mesh.

http://www.users.otenet.gr/~meenseto/g1.jpg

The boundary layer must be maked at a edge of airfoil.

mahi December 9, 2008 23:36

Re: BOUNDARY LAYER MESH
 
kostas, if the whole domain is a part of a circle, you can do one thing, delete the faces to teh left of the domain, and reflect the faces to the right about the centre axis. You didn't even have to make the 4 quarters. You could then just make one quarter, reflect it about any axis, and then reflect the resultant 2 faces in the same way. Then you need to connect edgesusing the edge connect option. Or else, you can link the face meshes and proceed with the meshing.

mahi December 9, 2008 23:52

Re: BOUNDARY LAYER MESH
 
Ignore my earlier mail. The thing is that in your case, the boundary layer will get deformed at the ends as there is already a mesh on the right side. The thing is that you first put an edge mesh on the aerofoil surface. Then go for a boundary layer. On the outer surface(circle), have the same number of intervals as you have on the aerofoil surface. It would be better if you connect join the edges that form the aerofoil (looks like you have the aerofoil surface made of many edges). If you are going for a quad mesh, the the no of intervals on the right unmeshed edge and the horizontal edge should be the same. For the small facenear the centre, same applies. Mesh the small face first. Then proceed further.

kostas December 10, 2008 13:54

Re: BOUNDARY LAYER MESH
 
Why can not make mesh up the boundary layer??? Why the up place of boundary layer hasnt nodes??? Is there a produse for make mesh up the boundary layer without compute the appearenceof boundary layer...

mahi, i do this which you tell me but the same state...


sushil December 11, 2008 05:05

Re: BOUNDARY LAYER MESH
 
Hi Kostas,

I think, it would be better if you check your geometry first. with the first figure you posted I suspect that these are two different faces you are trying to mesh. Please check that the faces you are trying to mesh are connected properly and there is no extra face.

Regards, Sushil

kostas December 11, 2008 08:51

Re: BOUNDARY LAYER MESH
 
With "The boundary layer tool", you have the capability to make a real mesh or make a help control mesh (not real but as driver of real mesh)????

sushil December 12, 2008 00:16

Re: BOUNDARY LAYER MESH
 
Boundary layer is not meant to creat mesh. It just helps you to distribute your cell sizes when you mesh the domain or face.


kostas December 12, 2008 05:53

Re: BOUNDARY LAYER MESH
 
ok... I find the problem....!!!! I put the 2.3.16 edition of gambit... and i do the same procedure. The mesh was fine.... May , there is problem at gambit 2.2.3 .. I dont know...


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