[Kevintyc]

Hello everyone,

I am currently working on a project simulating the changes in the etching boundary caused by the etching reaction. I attempted to compile a UDF, load the etchant concentration, and use a dynamic mesh to drive the movement of the etching boundary. While I successfully loaded the UDF, an error occurs, causing Fluent to crash when I start the computation. Below is my UDF code. I am a beginner with UDFs, and I would appreciate any assistance. Thank you.

#include "udf.h"

DEFINE_GRID_MOTION(etching_deformation, domain, dt, time, dtime)
{
Thread *tf = DT_THREAD(dt);
face_t f;
cell_t c;
Node *v;
real etch_rate, etch_depth, total_etch_depth;
real NV_VEC(origin), NV_VEC(etch_dir), NV_VEC(current_pos);
real local_concentration;
real base_etch_rate = 0.5;
int species_index = 0;
int n;

SET_DEFORMING_THREAD_FLAG(THREAD_T0(tf));

c = F_C0_T(f, tf);
local_concentration = C_YI(c, tf, species_index);
NV_D(etch_dir, =, 1.0 * local_concentration, 0.5 * (1.0 - local_concentration), 0.0);

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);


etch_rate = base_etch_rate * local_concentration;


etch_depth = etch_rate * time;
total_etch_depth = etch_rate * (time - dtime);

NV_VV(current_pos, =, NODE_COORD(v), -, origin);


NV_S(current_pos, +=, etch_depth * NV_DOT(current_pos, etch_dir));


NV_V(NODE_COORD(v), =, current_pos);
}
}
}
end_f_loop(f, tf);
}