Can anybody tell us why Fluent does not interpret UDF with random functions calls (srand, rand)? The error message says that srand and rand are "undeclared variables"... thanks gino

----------------------------------- #include "udf.h" #define RAND_MAX 32767

DEFINE_PROFILE(temp_face,t,i) { real x[ND_ND]; face_t f;

float ran ;

srand( (unsigned) time (NULL) );

begin_f_loop(f,t)

{

ran = rand()/float(RAND_MAX) ;

F_CENTROID(x,f,t);

F_PROFILE(f,t,i) = 310.+2.*(ran-0.5);

} end_f_loop(f,t) void srand( unsigned int seed ); } -------------------------------------

Ciao Gino, try to compile your UDF. The problem should disappear.Luca

thanks so much Luca, you are right, now it works! ciao gino