CFD Online Discussion Forums

CFD Online Discussion Forums (
-   CFX (
-   -   Re-Mesh boundary "contraction" (

Axlex May 23, 2013 11:01

Re-Mesh boundary "contraction"
3 Attachment(s)

i have a problem and hope you can help me. I have an assembly consisting of 2 cylinders and 1 pipe, which connects both. When the pistons are in motion, they move the fluid from 1 cylinder to the other and back.

In picture 1 u can see the mesh and picture 2 the state after the Re-Mesh-process. My problem is, that i don't know which Mesh Motion option i should use. The current ones are "Specified Displacement" for piston (no. 1) in picture 1, "Unspecified" for the cylinder walls (no. 2) and "Stationary" for no. 3.

At "Part Map" in the Remeshing options i entered the boundaries with the numbers 1 and 2. For the pistons (1) it works, because the boundary moves. For the cylinder walls it isn't functioning, because the walls arent getting "contracted".

How can i solve this problem? Thanks in advance for any help.

Axlex June 3, 2013 05:08

1 Attachment(s)
Hi again,

this note "only translational mesh motion is automatically handled by the ICEM
CFD Replay remeshing option" from the CFX Reference Guide, explains, why it isn't functioning.

My solution now is, that manage the contraction of the sidewalls is managed in my Replay file. The steps are:

1 Get the current simulation values with the program cfx5mondata.exe
2 close the old .tin file and create a new one with the current values
3 Remesh this new geometry

I have attached a file with the steps, to get these values, as it took some time to get it working.


All times are GMT -4. The time now is 19:02.