Scheme variable problem
 

Dear users,

I have written a UDF as below: no problem in compiling but when i run Fluent, there is an error message,

DEFINE_EXECUTE_AT_END(heat_flux)
{
Domain *d;
Thread *t;
face_t f;
real A[ND_ND];
real q;
real T_W;
real htc;
real q_t;
real TT = RP_Get_Real("T-ref");
d = Get_Domain(1);
t = Lookup_Thread(d,3);

begin_f_loop (f,t)
{
F_AREA(A,f,t);
q = WALL_HEAT_FLUX(f,t); /* gets the TOTAL Heat flux vector at the surface */
q_t = q / NV_MAG(A);
T_W = F_T(f,t);
htc = ABS(q_t / (T_W - TT));
C_UDMI(F_C0(f,t),THREAD_T0(t),0) = q_t;
C_UDMI(F_C0(f,t),THREAD_T0(t),1) = htc;
}
end_f_loop (f,t)
}

The following error message appears:

Error: rpgetvar: T-ref: undefined variable
Error Object: ()

I have already defined T-ref using
(if (not (rp-var-object ‘T-ref))(rp-var-define ‘T-ref 290 ‘real #f)) in TUI so I think there should be no problems!
I will appreciate if you can help me resolve this problem,
tnx