# a mesh motion question

 Register Blogs Members List Search Today's Posts Mark Forums Read

 March 3, 2011, 03:40 a mesh motion question #1 New Member   John Join Date: Mar 2011 Posts: 7 Rep Power: 15 Dear all, I am working on a fsi case. The fluid model can work well before mesh motion is turned on. But if I used mesh motion, even without fsi, it got overflow quickly. Even if I use the result of static mesh case as the initial condition of mesh motion case, it still can not work. Please help me if anyone know how to solve this problem. Thank you so much! John

 March 3, 2011, 17:45 #2 Super Moderator   Glenn Horrocks Join Date: Mar 2009 Location: Sydney, Australia Posts: 17,819 Rep Power: 144 Some details of what you are doing might be useful......

March 3, 2011, 21:34
#3
New Member

John
Join Date: Mar 2011
Posts: 7
Rep Power: 15
Quote:
 Originally Posted by ghorrocks Some details of what you are doing might be useful......
There are two domains in my fluid model: water and porous. I used mesh motion in water domain. The problem is, even no fsi, just the fluid model itself, it gets overflow all the time. In the output file, all the mesh deformations are 0, which means the mesh is exactly the same with static mesh case.

 March 6, 2011, 16:59 #4 Super Moderator   Glenn Horrocks Join Date: Mar 2009 Location: Sydney, Australia Posts: 17,819 Rep Power: 144 So you are saying that you turn mesh motion off and it converges but you turn mesh motion on, but specify zero displacement it diverges?

March 15, 2011, 21:24
#5
New Member

John
Join Date: Mar 2011
Posts: 7
Rep Power: 15
Quote:
 Originally Posted by ghorrocks So you are saying that you turn mesh motion off and it converges but you turn mesh motion on, but specify zero displacement it diverges?
Yes. It's so strange.

 March 16, 2011, 10:54 #6 Senior Member   Edmund Singer P.E. Join Date: Aug 2010 Location: Minneapolis, MN Posts: 511 Rep Power: 21 Make your water slightly compressible.