Discussion Forum

Hello,
I'm currently trying to set up a bubble growth model in a viscoelastic material, and it seems that I'm going to need a moving mesh (the grow of the bubble can, sometimes, become large enough to do so).
I use a specific set of equations to model the viscoelastic behavior of the material, using the weak form formulations for a 2-D Axisimmetric geometry.
Doing so, I cannot change the properties of the model using the Physics > Subdomain settings, but use a set of constants and expressions instead. No big deal for now.
Trouble is, when using ALE I also cannot access the options for the moving mesh in the Physics > Subdomain settings ALE dialog box.
In order to understand how to implement the moving mesh in the weak form, I'm creating a simple elastic version of my model. I want my mesh to follow the displacements of the material, so I've put uaxi_axi and w in the Physics induced displacement boxes. But I can't see where it is set in the Physics > Equation system > Subdomain settings dialog.
However, when I set the mesh to have Free displacement in the Physics > Subdomain settings ALE dialog box, I can see those term appear in the weak terms :

-rRt*test(rR)-rZt*test(rZ)
-zRt*test(zR)-zZt*test(zZ)

I was just wondering if someone had a clue of how to implement the physics induced displacement in a custom set of equations.
Thanks in advance for any reply.
Y.