ALE usage

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Arnaud Andlauer

ALE usage

Post by Arnaud Andlauer »

Hello,

I'm trying to use ALE, but i don't good understand how to use it.

Is there an example, including meshes and user routines. If so is it possible to have them.

Thank you for your reply
Alexandre Douce

Re: ALE usage

Post by Alexandre Douce »

Hi,
you can find an example of an application with a mobile mesh here:
https://code-saturne.info/products/code-saturne/forums/flow-modeling-examples/868717903/884723847
In this demo case, the displacement of the structure is due to the fluid. In Code_Saturne, you can also prescribe the motion of the boundary structure.
Arnaud Andlauer

Re: ALE usage

Post by Arnaud Andlauer »

Sorry for my late reply.

Thank you for the link.

I understand better the ALE usage.

I want to do this:
move an entire wall (box) in a fluid domain.
the speed of moving wall is constant.

the result there is a movement in the box but not in the fluid domain.

Would you have any suggestions or advice.
Arnaud Andlauer

Re: ALE usage

Post by Arnaud Andlauer »

Hello,

Our problem is some how similar to the problem attached below. We have difficulties to set the right boundary conditions. In order to move a part of the domain, should the grid be constituted of two completely independent parts or the part in movement and the fixed one must share one properties?: In fact we need to move a part of the domain by imposing a displacement velocity without having a big influence on the cells of the main fixed domain that are far from the moving part. The fluids effect on the structure is not of big interest for us, we only care about the effect of the structure on the neighboring fluid.

Please refer to the mesh below:
Attachments
superposition-de-maillage.jpg
Alexandre Douce

Re: ALE usage

Post by Alexandre Douce »

Previously Arnaud Andlauer wrote:
Sorry for my late reply.

Thank you for the link.

I understand better the ALE usage.

I want to do this: move an entire wall (box) in a fluid domain.
the speed of moving wall is constant.

the result there is a movement in the box but not in the fluid domain.

Would you have any suggestions or advice.
Hi,
For moving a wall, there are 2 cases :
1) if the movement of the rigid wall is inside the same plane of the boundary condition, you should use the "sliding wall" option in the GUI. This option does not change the mesh. A famous example is the Lid-driven cavity flow.
2) if the movement of the wall involve the deformation of the grid you should use the "mobile mesh" option in the GUI. Then you have to impose the displacement of your boundary condition.
 
 
Alexandre Douce

Re: ALE usage

Post by Alexandre Douce »

Previously Arnaud Andlauer wrote:
Hello,

Our problem is some how similar to the problem attached below. We have difficulties to set the right boundary conditions. In order to move a part of the domain, should the grid be constituted of two completely independent parts or the part in movement and the fixed one must share one properties?: In fact we need to move a part of the domain by imposing a displacement velocity without having a big influence on the cells of the main fixed domain that are far from the moving part. The fluids effect on the structure is not of big interest for us, we only care about the effect of the structure on the neighboring fluid.

Please refer to the mesh below:

The attached image show

The image shows another a CHIMERA grids computation : it is involve two or more overlapping grids. It is only for large displacement. It seems is is not your case.
Arnaud Andlauer

Re: ALE usage

Post by Arnaud Andlauer »

sorry I've not described my problem enough. I work on movement induced by a moving solid. I attached a Schematic of the study. I have large displacement I manage to move the field without distortion of the mesh. I have problems in defining the boundary conditions. Because part of my moving domain get out of the field fluid domain.
Attachments
forum-modile-mesh.jpg
Matthieu Guillaud

Re: ALE usage

Post by Matthieu Guillaud »

Hello,
you can find an example close to your case on the "Flow modeling examples" section : Inner flow in a piston.
 
 
https://code-saturne.info/products/code-saturne/forums/flow-modeling-examples/961298668
Hope it can be helpful.
 
Regards.
Matthieu Guillaud                
Guest

Re: ALE usage

Post by Guest »

HI Alex
 
i am working on the internal coupling of saturne, do you know anything about the displacement predictions in internal coupling .
 
If so please tell me the importance of the variables.
 
and also what does the Maximum number of sub-iterations for implicit coupling with internal structures
means in the internal coupling.
 Because i didn't found any thing relate to it so please help me
 
thanking you in advance
 
with regards
 
thejaraju
 
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