Fluent 3D Dynamic Mesh
 

I have to make a dynamic mesh that can change the radius of a cylinder. How can I make the .udf?

YOU CAN ALSO ADD z DIRECTION

DEFINE_GRID_MOTION(RADII, domain, dt, time, dtime)
{

Thread *tf = DT_THREAD (dt);
face_t f;
Node *v;
real x_coor;
real x_centre=0;
real y_coor;
real rayon;
real freq = 3.183;
real alpha;
real temps;
real R =0.25;
int n;
// FILE *fp = fopen(UDF_FILENAME, "r");

/* set deforming flag on adjacent cell zone */
SET_DEFORMING_THREAD_FLAG (THREAD_T0 (tf));



//temps = RP_Get_Real("flow-time");
temps = time+dtime;
begin_f_loop (f, tf)
{
f_node_loop (f, tf, n)
{
v = F_NODE (f, tf, n);
if (NODE_POS_NEED_UPDATE (v))
{
NODE_POS_UPDATED (v);

x_coor= NODE_X (v);
y_coor= NODE_Y (v);
alpha = 0.125;

NODE_X (v) = x_coor- x_coor*(alpha*cos(2*M_PI*4*freq*temps));
NODE_Y (v) = y_coor- y_coor*(alpha*cos(2*M_PI*4*freq*temps));

}

}
}
end_f_loop (f, tf);
}