[mollybinni]

Hi everyone. I have a simple box that I am trying to deform. I want to move all nodal x coordinates by 0.5 mm at 20 seconds. This is only applied to the wall. When I use my UDF in ANSYS Fluent, however, nothing happens when previewing the mesh movement. What I am I doing wrong?

Here is my code:
#include "udf.h"

DEFINE_GRID_MOTION(moveit,domain,dt,time,dtime)
{
Thread *tf = DT_THREAD(dt);
face_t f;
Node *node;
int n;
real current_time;
current_time = CURRENT_TIME ;

real NV_VEC(vetcoord);
vetcoord[0] = 0.5 ;
vetcoord[1] = 0 ;
vetcoord[2] = 0 ;

SET_DEFORMING_THREAD_FLAG(THREAD_T0(tf));


begin_f_loop(f,tf)
{
f_node_loop(f,tf,n)
{
node = F_NODE(f,tf,n);

if (NODE_POS_NEED_UPDATE(node) && current_time == 20)
{

NODE_POS_UPDATED(node);
NV_V(NODE_COORD(node), +=, vetcoord);

}
}
}

end_f_loop(f,tf);
}

Any ideas are welcomed and thanks for the help!

EDITED: I need to use Define Grid Motion because the final UDF will involve different displacements for each node. Right now this is a just a simplified version for debugging.