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-   -   how to read a 3D trajectory for CG_MOTION (http://www.cfd-online.com/Forums/fluent/124356-how-read-3d-trajectory-cg_motion.html)

Bollonga October 3, 2013 05:29

how to read a 3D trajectory for DEFINE_CG_MOTION
 
Hi everybody,

I'm using a UDF with DEFINE_CG_MOTION to define the movement of an object in a 3D fluid domain. The path followed by the object is an irregular path so I wonder if there is a way for the macro to read a vector of positions instead of a mathematical description?

Thanks a lot

like.no.other October 5, 2013 13:38

Hi
You can do this with a profile
It is very simple

Bollonga October 5, 2013 13:40

Quote:

Originally Posted by like.no.other (Post 455236)
Hi
You can do this with a profile
It is very simple

Could you please explain me how to use a profile? Thanks a lot!

like.no.other October 5, 2013 14:12

1 Attachment(s)
Quote:

Originally Posted by Bollonga (Post 455237)
Could you please explain me how to use a profile? Thanks a lot!

first you should create a file with prof extension (*.prof) like the attached picture.
in profile you can define the time dependent variables (v_x,v_y,v_z,omega_x,omega_y,omega_z)

for example in this profile the angular velocity in z direction is defined.

at the end you should read it in fluent.

Bollonga October 7, 2013 07:25

Thanks a lot! You've been of great help!

Bollonga August 18, 2014 06:45

What happens when the profile timestep is larger than the solver timestep? Does it linearly interpolate the position between the two profile timesteps?

Any help would be greatly appreciated. Thanks.


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