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udf_users_newbee November 21, 2009 13:36

Motion UDF
 
Hi,

I'm a student and have little expiriences in using the 6DOF solver and dynamic meshes in Fluent.

My problem:

I want to calculate the free fall motion of a 2D-Body in water (vof) in an open channel flow.
Normally, i use the 6dof motion and the dynamic mesh.

Now, i want to calculate the motion, but without using a dynamic mesh. What i would like to do, is to "move" the water volume fraction instead of the body. I think, i have to update the boundary conditions, the free surface and the velocity in every cell.

I've no expirience writing UDF's. Is ist possible to "read" the body velocity and buoyancy forces and "update" domain with this data in every timestep?


Thanks for your help.


best regards

sven

Jessica.S May 5, 2012 20:54

did you manage to solve the problem?

udf_users_newbee May 6, 2012 03:52

Hi,

yes i did, but not for freefallmotions. I use it for calculating ship motions in waves. I think it could be used for freefallmotions too, but i didn't test it yet.
I use three udf's to calculate position of the phaseboundary at inlet and outlet and the volume fraction at the domain. So i can use 6Dof in an open channel without meshmorphing.

Sven

dragonship2011 May 31, 2013 04:42

Quote:

Originally Posted by udf_users_newbee (Post 237177)
Hi,

I'm a student and have little expiriences in using the 6DOF solver and dynamic meshes in Fluent.

My problem:

I want to calculate the free fall motion of a 2D-Body in water (vof) in an open channel flow.
Normally, i use the 6dof motion and the dynamic mesh.

Now, i want to calculate the motion, but without using a dynamic mesh. What i would like to do, is to "move" the water volume fraction instead of the body. I think, i have to update the boundary conditions, the free surface and the velocity in every cell.

I've no expirience writing UDF's. Is ist possible to "read" the body velocity and buoyancy forces and "update" domain with this data in every timestep?


Thanks for your help.


best regards

sven

the same to you. I read some paper,but that is a sercet. I don't have any answer even though I had communicate with the author.

udf_users_newbee May 31, 2013 05:04

Sorry, but i don't understand your problem.
What do you want to say to me?


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