udf problem
 

I am running a simulation in which the heat flux from the wall to the fluid flowing inteh channel varies linearly with the x co ordiante (independant of the other co ordiantes) i wrote the udf for it but it gives this error every time i run it.

chip-exec: heat_flux: argument 1: incorrect type (31): int expectedchip-exec: heat_flux: argument 2: incorrect type (5): pointer expectedchip-exec: heat_flux: argument 3: incorrect type (-842150451): int expected Error: FLUENT received fatal signal (ACCESS_VIOLATION) 1. Note exact events leading to error. 2. Save case/data under new name. 3. Exit program and restart to continue. 4. Report error to your distributor. Error Object: ()

my udf program is as folows

#include<udf.h> #DEFINE C1 39682.5 #DEFINE C2 2645502.646

DEFINE_PROFILE( heat_flux,thread,i) { real pos_vec[ND_ND]; real x; face_t f; begin_f_loop(f,thread) { F_CENTROID(pos_vec,f,thread); x=pos_vec[1]; F_PROFILE(f,thread,i)=C1 - C2*x; } end_f_loop(f,thread) }

please help me thanks in advance