Change geometry during unsteady run
 

Hi
How to increase/decrease the length of a 3d cube online in an unsteady run

You have to be far more specific. Do you want to remesh during the run? Are you just morphing? How is the cube generated?

yes' I want to remesh during the run.I generated the cube using the Geometry in star_ccm as an initial cube which I want to chage during the run,i.e decreasing/increasing one of th three dimentions. Home I am clearer now ?

If you generated a cube you will not be able to change the size dynamically with remeshing. In order to change the size and remesh, you need the cube to be built in 3D-CAD and you will use a design parameter to change the size.

I don't think that's what you want to do, though. If you want to do this with a transient run, it's far more likely you want to morph the mesh you have (i.e. just stretch the grid in one dimension). Does that sound right?

If that's the case you just need to make a morpher motion, apply the motion to the region, and then assign a movement condition (grid velocity or something like it, you can look up the options in the user guide) to the side of the cube you want to stretch. Set the 4 sides that touch it as floating.

If you generated a cube you will not be able to change the size dynamically with remeshing. In order to change the size and remesh, you need the cube to be built in 3D-CAD and you will use a design parameter to change the size.

I tried to do the last thing you suggested, but couldnt manage to change the cube. Couldnt find the right option in the user guide. Could you show me where to get it ?
About your 3D-CAD comment. The Geometry option which is build in the STAR-CCM isnt a 3D-CAD tool ? As I mentioned, I used it to build the cube.

The user guide has a tutorial on using the morpher in a very similar application. Look at Tutorial guide>Motion>Morphing

If you made the cube by right-clicking the Parts folder and told it create shape>box, then no, that box is not a CAD representation. The only method for CAD generation in STAR-CCM+ is by using the 3D-CAD utility.

I made the cube by right-clicking the 3D-CAD Models and creating a New Geometry Part (by right-clicking on the new model 3D-CAD Model 1). Isnt it a CAD generation ?
I already used the tutorial you suggested, and foloowed the instructions in it, but my cube remain unchanged in any direction

Yes, that particular method of making the cube is CAD.

What did you use for the morpher BC on the moving face?

Thanks for your help. I managed to run my case. I used the the displacement option for the moving surface and floating for the suefaces connected to it.
But, somehow I could run it only as a 2D case. Trying to run the 3D option I got negative volumes when the gopher was activated. I tryed several ways of meshing but it didnt help ! How can I solve this problem ?

Please post some images of your mesh and label the BCs. I thought you were running 3D from the beginning since you said cube...

Morphing and Translation
 

Hi everyone
I have a 2D case of two square regions combine with an interface
One of them should Morph at a certain velocity while the should
translate at the same velocity folowing the Morhing of the first
The result is that only the the second region Translates whule the first one
doesnt Morph !!! A gap is performed between them but they should remained contacted.

Any idea ??