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-   -   cg motion-udf-dynamic mesh (http://www.cfd-online.com/Forums/fluent-udf/97871-cg-motion-udf-dynamic-mesh.html)

omidvar February 27, 2012 17:15

cg motion-udf-dynamic mesh
 
I wrote a simple UDF code for describing pitching motion of a
projectile as below:
#include"udf.h"
DEFINE_CG_MOTION(pitching,dt,vel,omega,time,dtime)
{
omega[2]=20.0*cos(10.0*time*3.1416/180.0);
}

But when I wanted to create dynamic mesh zone, Fluent reports:
"Warning: incorrect cg motion UDF pitching on zone 10 (assuming no motion)"
I confused, I searched udf manual and cfd online forums but I couldn't
find the reason of problem.
If someone know the solution please help me.

Spring.s March 11, 2012 04:50

Hi dear Amir
I think that the using udf for your case, is very short!
Too, i think that You must define Thered in udf.

omidvar March 12, 2012 14:51

Quote:

Originally Posted by Spring.s (Post 348756)
Hi dear Amir
I think that the using udf for your case, is very short!
Too, i think that You must define Thered in udf.

Hi dear Spring
Whould you please explain more?
what is Thered in udf?

Spring.s March 14, 2012 00:21

Hi
There is one example in UDF manual about one directional motion that use Thread for define moving wall in fluent

vasava March 26, 2013 03:03

I think that you must have something else in your UDF that describes the motion/position of other faces/boundaries in your domain. While you have moving/dynamic face/boundary the motion of mesh attached to this face affects the meshes attached to other faces/boundaries.

I suggest you have a close look at the tutorial titled 'Using a UDF to Control the Dynamic Mesh of a Flexible Oscillating Membrane'.

nitman118 June 7, 2013 03:10

hey vasava could you provide us with the tutorial or maybe point us out where its located....thanx

nitman118 June 7, 2013 03:38

hey vasava could you please send me the tutorial on : nitman118@yahoo.com....will be a great help....thanks

poriaFoam July 14, 2013 01:47

Hi Mr omidvar
I had same problem like you, and i found it depends on your fluent version, i guess you use fluent x64, if you use from x86/x32 it will solve.

hamed1987 February 21, 2016 01:17

hi omidvar,
if you describe your case ,
maybe i could help you,
what is your case and what do you want ???
what is your mesh zone setup??
i think you have a problem in dynamic mesh setup


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