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-   -   [ANSYS Meshing] Dynamic meshing of a deforming body (https://www.cfd-online.com/Forums/ansys-meshing/178776-dynamic-meshing-deforming-body.html)

aero_cfd October 16, 2016 05:38

Dynamic meshing of a deforming body
 
Hello,

I have a mathematical formula that gives the coordinates of a deforming 2D body, and I would like to use them in order to create the body and the dynamic meshing around it , how should I approach it ? does it require a UDF ?

Thanks

vasava October 17, 2016 01:16

You will certainly need UDF. The UDF setup and macro usage will depend on how the boundary is moving and deforming. Re-meshing could be handled by setting up dynamic mesh zone.

Without any technical details about the problem, it is very difficult to help you. Perhaps you can go through some dynamic mesh tutorials such as check valve simulation using Dynamic Meshes, Simulating a Gear Pump Using Dynamic Mesh with 2.5D Re-meshing, Using a UDF to Control the Dynamic Mesh of a Flexible Oscillating Membrane etc.

aero_cfd October 17, 2016 05:46

Thanks for the answer, the problem is as follow , I have two curves that makes up a body upper and lower surface, so the geometry is defined by two equations have parameters changing by time so the geometry will deform.

The issue is how to do the meshing around the geometry where all I have are the equations and therefore the coordinates in each time time step.

All the tutorials mentioned start from a given defined geometry imported into the mesher then it will be be rotated or deformed.

Is it more clear ?

vasava October 18, 2016 02:53

Quote:

Originally Posted by aero_cfd (Post 621755)
All the tutorials mentioned start from a given defined geometry imported into the mesher then it will be be rotated or deformed.

The UDF for Flexible Oscillating Membrane tutorial has a part where an interface is deforming according to some equation and the mesh around the deforming interface is re-meshed. You can try to introduce a time dependent equation instead and see how it goes. Macros such as PREVIOUS_TIME, CURRENT_TIME, CURRENT_TIMESTEP etc. could be used to get time information.

aero_cfd October 28, 2016 05:36

is it possible to get this tutorial with the files . i wasn't able to find the files and UDF ?

aero_cfd October 29, 2016 06:13

I already got the files and went through the tutorial.
in the C file you have the DEFINE_GEOM function , does it define the plane or the plane is already defined when you draw the geometry then you mesh it? because it seems this is the case, then what does the DEFINE_GEOM do ?

vasava October 31, 2016 04:46

In this tutorial DEFINE_GEOM defines the plane which is represented via an equation. In the tutorial the UDF is applied to the top wall. The macro causes the moving mesh to slide on the top wall and the near by nodes to project on the wall in order to keep the shape of the wall intact.

You can make an animation of the moving mesh and you will notice this. I hope this helps.

vickyrs April 16, 2019 03:11

Quote:

Originally Posted by aero_cfd (Post 623391)
I already got the files and went through the tutorial.
in the C file you have the DEFINE_GEOM function , does it define the plane or the plane is already defined when you draw the geometry then you mesh it? because it seems this is the case, then what does the DEFINE_GEOM do ?

Hi, can you share this tutorial files if possible.:)


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