Mesh motion on inlet (2-way FSI)
 

Hi,
Im doing coupled 2-way FSI on basically a long pipe with both a fluid and a solid part. The solid is free to move in radial direction and has a zero displacement boundary condition in axial direction on the in and outlet. The fluid part on the other side, has mesh motion set to "Unspecified" on the in and outlet, to let it follow the solid parts motion in radial direction. I get a warning saying:
"Mesh motion is specified on the boundary 'inlet'. This is valid for motion that is tangential to the boundary but solution errors will occur if motion is normal to the boundary".

Well, I only want the inlet to move in radial direction, but after a couple of 1000 timesteps the fluid part starts to move in axial direction and the solution diverges. Is there a way to set an axial zero displacement on the fluid part as well when doing coupled 2-way FSI?

Lance

2-way fsi
 

Hi:
You can build model (structure model)in ansys, fluid model is built in cfx.
THen use the mesh motion.

Maybe I was unclear (?). I have set up my solid model in Ansys Mechanical and my fluid model in CFX. It is a 2-way FSI, using both solvers.