[Aidan100]

Hey,

I'm learning how to use UDF's in order to set up a transient solver within fluent to test for dynamics involved with a morphing wing in between steady state solutions/morphing.

I am beginning with a simple 2D case and trying to learn how to rotate and translate basic objects in 2D (before progressing to 3D). I am trying to simulate the rotating cylinder to achieve lift and have attached the following UDF which should be able to define the rotational motion about the z-axis. (Source: http://projekter.aau.dk/projekter/fi...Enclosures.pdf)


/************************************************** *********************
udfexample.c
UDF for rotation of cylinder
************************************************** **********************/

# include "udf.h"
DEFINE_CG_MOTION ( rotation_udf_45 , dt , vel , omega , time , dtime )
{
real pi = 3.141592;
real omega_constant = 45* pi /180;
omega [2] = omega_constant ;
}




However after interpreting my UDF and applying it to the cylinder (zone 8) within the Dynamic Mesh menu bar it says:

"Warning: incorrect cg motion UDF rotation_udf_45 on zone 8 (assuming no motion). "


Indeed there is no motion occurring when the preview mesh motion is selected. How can I solve this problem?