Mesh convergence problem
 

Hi, I have a problem about mesh convergence.

My problem is a 2D jet impingement on a moving wall. After a VOF simulation and guess the interface between the liquid and the air, i do a simulation like a laminar pipe flow problem (with just the liquid)

The boundaries condition are shear stress equal at 0 at the free interface and no slip condition+ velocity for the moving wall. I have also a edge for flow inlet and one for pressure outlet. You can see the geometry with the mesh in the attach files

I do a mesh refinement study by doubling the number of cells in each direction twice. But, i don't have a mesh convergence but something like a depressure offset (see "pressure at the wall" in the attach files).

When I try do the same study with a stationary and no slip wall in place of moving wall, I have a mesh convergence.

I don't what's wrong. I try setting to no slip and just the areas very close to where the free surface interface meets the surface, but it's not better...

Someone of you are already confronted at this problem ?

Thanks