[mataus]

Hai CFD user
I would like to add energy source term to my problem.
I wrote UDF and compiled it.(no issues)
but I am getting an error at the end of 20 iterations.
This error always occurs at the max number iteration step, for example, if I increase max iteration to 50 error occurs at 50th iteration at the first-time step.
udf code

DEFINE_ON_DEMAND(solid)
{
Domain *d=Get_Domain(1);
int zone_id=11;
Thread *t = Lookup_Thread(d,zone_id);
cell_t c;
begin_c_loop(c,t)
{
C_UDMI(c,t,0) = 0.1;
}
end_c_loop(c,t)
}

DEFINE_EXECUTE_AT_END(source_calculation)
{

Domain *d;
Thread *t;
cell_t c;
real dt=CURRENT_TIMESTEP;
int zone_id=11;
thread_loop_c(t,d)
{
begin_c_loop(c,t)
{
C_UDMI(c,t,1)=C_T(c,t)/some constant;
C_UDMI(c,t,2)=0.01;
C_UDMI(c,t,0)=C_UDMI(c,t,0)+(C_UDMI(c,t,2)*dt);
}
end_c_loop(c,t)
}
}

DEFINE_SOURCE(energy, c, t, dS, eqn)
{
real x[ND_ND];
real source;
source = some constant* C_UDMI(c,t,2);

dS[eqn] = 0;
return source;
}

[KaLium]

= Error at the end of timestep