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Paul_321 July 29, 2009 12:39

Dynamic Mesh problem

I have a simple case where I am moving a wall, with a UDF. I picked the zone in "dynamic zones" and pick a rigid body motion and selected my UDF. I have layering option picked. All looks ok, however when I view zone motion the wall moves as it should. How ever at the end of the wall, there 2 adjecent face do not move. I have tried to select these a deforming zones etc. When i select solve mesh motion, notting moves or changes.

Do i need to specify any deformation for the interior mesh?
What do I need to specify for these 2 adjecent zones? I have tried a number of options but notting working


-mAx- July 30, 2009 02:07

Is the creation / deletion for cells running good (layering)?

Paul_321 July 30, 2009 05:59


I can just see the one zone move in "zone motion" The zone that has teh UFD attached to it. Notting is happening in solve-mesh motion. I have saved hardcopy files, but they all are the same?

-mAx- July 30, 2009 06:49

have you set the mesh options for your rigid body?
as it is moving, the adjacent cells should be created/deleted

wangruixing July 30, 2009 07:12

i think you need to change the moving type of the mesh ,change the moving type to moving reference fram.

Paul_321 July 30, 2009 08:38

I am trying to make a gap smaller, so I used one face as the rigid body and move it up to wards the opposite face. Its the side walls that are causing the problem. Think of teh problem and my area is a rectangle and I am trying to reduce the height
I will try to change the mesh and see what happends,

Thanks for the input guys

-mAx- July 30, 2009 08:59

check the tutorial about dynamic mesh (it is about layering)

Paul_321 July 30, 2009 09:43

tutorial 10, is close to what I need to do in reagard to the dynamic mesh. I will try this out and see what happens!


udayrg July 31, 2009 07:11


I guess in layering options check the sizes you have set for layer addition and subtraction. This is the limit for cell hieght that controls the layering. In-case if you have put in a larger limit it would behave like wise. that is it will keep on stretching the last cell hieght with given motion to dynamic zone.

Paul_321 July 31, 2009 08:03

I have looked through the tutorial, and i seamed to be doing things ok.
I have a question on the sequence of how the problem.
I set up my dynamic zone
I preview the zone motion, ...........display - zone motion
The zone is moving like I want it to move.
Now what next, do I ........solve - mesh motion (the tutorial doesn't mention this)
I can set up a window with some value like velocity and set this to record every time set etc, hardcopy.
If I go to solve and solve my problem, the mesh still doesn't seam to move, am I missing something hear?


-mAx- August 3, 2009 00:40

first you may check if your mesh is moving right (solve/mesh motion)
enable display grid, and check if the layering occures.
But if you don't get any warning/error regarding the mesh, AND if your mesh doesn t seem to have any motion, then the motion of your body isn't right described.
To be sure switch your udf to an profile witch constant velocity, and re-check your mesh motion

Paul_321 August 11, 2009 11:32

:eek:Got the dynamic mesh working in the end.I had the wrong velocity in my UDF, i changed it to suit my time step.
Thanks guys for your input.


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