Learning Forum

[Duke711]

In fleunt dynamic mesh option the remeshing does not work in boundary by deforming wall. See what happend, some people here seem to have had this problem.

 

 

The boundary cells on defined deforming wall only ceep stretching, not remeshing. Same problem on 2D Mesh. I think it is a bug. Dynamic mesh option is smoothing and remeshing with maximum cell local size with 1 mm.

Was someone able to solve the problem?

Fluent seems to have the problem with defined deforming wall by a tetrahedron mesh. In the Ansys examples shown, you always see a layering zone with hex mesh. With ist not possible here, because here overlapping the valve with the combustion chamber.

Piston ist a rigid body motion. The liner walls a deforming wall. Smoothing diffuse and local cell size remeshing.

 

 

 

[Federico Alzamora Previtali]

Hello, 

can you include screenshots of your Dynamic Mesh settings? Are you using Unified Remeshing Method or Methods-based remeshing?

[Duke711]

the settings:

 

[Federico Alzamora Previtali]

Thanks for sharing this screenshot, but which zone is the one shown in the original post?

Enable Region Face in the Remeshing methods to allow remeshing of the boundary zones making up your deforming zone.

Alternatively, you can select the Unified Remeshing method, which uses a combination of remeshing method and is simpler to set up. You can read more on the above in the User Manual 11.6. Using Dynamic Meshes (ansys.com)

[Duke711]

Not working:

• disable smoothing
• enable region face in the remeshing

1 time step, local remeshing works

 

after 3 time steps, cells on boundary ceep stretching:

[Federico Alzamora Previtali]

No need to disable smoothing.

Without the context of knowing which zone is which in your screenshot, I cannot suggest an exact solution for you. 

What is the name of the bottom boundary? What is the name of the yellow cell zone you are showing?

[Duke711]

Here is the case. Four eyes see more than two.

Thanks very much.

https://www.dropbox.com/s/ssle1t6ysfjf0tq/export.wbpz?dl=0

 

 

[Federico Alzamora Previtali]

I'm sorry but I cannot download your files. I can offer suggestions and recommendations based on the details that you share.

[Duke711]

• deforming wall (symmetry, wall-liner)
• rigid body motion (valve wall and piston wall)

The picture show symmetry Face and the bottom boundary is the piston wall -> rigid body motion, to moving down.

It would be better to look at the case directly, because I've actually tried everything. The download link sould actually work.

[JD_JN]

Hey, you can see what worked for me for a similar problem I had:

 

https://forum.ansys.com/forums/topic/dynamic-mesh-no-remeshing-happening-on-axis-boundaries/