[bojiezhang]

hello every former:

I use interDyMFOAM with moving mesh(displacementLaplacian), and I use the pointDisplacement to control the boundary motion.

when I set a small displacement for one boundary, at the first time step, all is ok and the internal mesh move formally.

but at the second time step, I find the mesh on the boundary distorted, and the internal mesh certainly also distorted. At the same time, the courant number become very large and the caculation terminated.

I feel confused if the displacementLaplacian is credible, for it can not be applied for such a small displacement.

Hope someone could tell me if I did something wrong.

Thank you!

bojiezhang

[kingle]

I've been investigating scour around objects. I know that when the amplitude of the boundary movement is big enough, the mesh may be highly distorted and make the computation not easy to converge, this is the limitation of mesh deformation approach. I advice you to try dynamic mesh approach, mesh cells can be split or merged when necessary, but this method is difficult.

[sxhdhi]

Dear Bojie

I would like to know whether you have solved your small displacement moving BC problem or not.
I also meet the same problem here.

[wyldckat]

Greetings to all!

Without an example, there isn't much anyone can do to help you, as explained here: How to give enough info to get help

Nonetheless, have a look into this post for ideas for a possible solution: http://www.cfd-online.com/Forums/ope...tml#post398703 post #12

Best regards,
Bruno