Learning Forum

[Ryan Liaw]

Hi, I am new to Ansys. I want to ask if the motion shown in the video below is possible with a dynamic mesh in Ansys Fluent and where can I get resources to learn how to do it if possible.

https://youtu.be/aI-l6Q2hhAs

The fluid region would be as shown below.

I would imagine the fluid domain to look like this in its initial and final stage. The inlet is static.

Initial Top:

Initial Bottom:   

Final Top:

Final Bottom:

I have seen examples of sliding mesh for 3D rigid bodies but all of them are rotating on their own axis through the influence of the fluid forces with 6DOF. I have also seen prescribed motions done with UDF in 2D.

However, I have not found any examples of prescribed motion done with a 3D model. If it is possible with the above methods, I would appreciate any links to resources that might help me make this possible.

Any help is appreciated.

[Federico]

Hello, 

You can find an example here to get you started  Ansys Fluent: Using the Six Degrees of Freedom (Six DOF) Solver - YouTube

For Dynamic Meshing, you can have any combination of prescribed motion in 3D or 2D and/or 6DOF.

Here, it seems to be that all motion is parallel with XZ plane:

• the direction of the rotation of the main disk is along the Y-axis;
• the direction of the rotation of the 2nd disk is along the Y-axis, with oscillation parallel to XZ plane;
• the oscillating motion of the arm is parallel to XZ plane.

Your would need 3 different DEFINE_CG_MOTION UDFs to characterize each of these movements. 2.6. Dynamic Mesh DEFINE Macros (ansys.com)