I am trying to write a time dependant udf using the CURRENT_TIME macro, however when I interpret the udf fluent gives an error decribing CURRENT_TIME as an undeclared variable.

My udf code:

#include "udf.h"

DEFINE_PROFILE(unsteady_velocity, thread, position)

{ face_t f;

real t = CURRENT_TIME;

begin_f_loop(f, thread)

{ F_PROFILE(f, thread, position) = 20. + 5.0*sin(10.*t); }

end_f_loop(f, thread) }

However if I use the Equivalent RP Macro, i get don't receive an error.

My new code: #include "udf.h"

DEFINE_PROFILE(unsteady_velocity, thread, position) {

face_t f;

real t;

t = RP_Get_Real("flow-time");

begin_f_loop(f, thread) {

F_PROFILE(f, thread, position) = 20. + 5.0*sin(10.*t); }

end_f_loop(f, thread) }

Can some explain to me how I am using the CURRENT_TIME macro wrong please so I can avoid these errors

Hm... Check that you have flow.h located in the right directory. It should be in the same directory as udf.h I guess. The CURRENT_TIME macro is defined in there and udf.h should link to it automatically.

/Henrik