[Tien wen]

Hello，everyone，
I have a Problem with function Compute_Force_And_Moment
My udf is :
#include "udf.h"
#define FORCE_OUTPUT_FILE "force.out"
#define MOMENT_OUTPUT_FILE "moment.out"

DEFINE_CG_MOTION(airfoil,dt,vel,omega,time,dtime)
{
FILE *fd1=fopen(FORCE_OUTPUT_FILE,"a");
FILE *fd2=fopen(MOMENT_OUTPUT_FILE,"a");
real x_cg[ND_ND];
real f_glob[ND_ND];
real m_glob[ND_ND];

Domain *domain= Get_Domain (1);
Thread *tf1 = Lookup_Thread (domain, 7);
x_cg[0]=0.05;
x_cg[1]=0.0;
x_cg[2]=0.2;
Compute_Force_And_Moment (domain, tf1, x_cg, f_glob, m_glob, TRUE);
fprintf(fd1,"%g,%g,%g,%g\n",RP_Get_Real("flow-time"),f_glob[0],f_glob[1],f_glob[2]);
fprintf(fd2,"%g,%g,%g,%g\n",RP_Get_Real("flow-time"),m_glob[0],m_glob[1],m_glob[2]);
omega[0]=-1.1*cos(1.57*time);
omega[1]=-0.411*cos(1.57*time+1.57)*sin(0.7*sin(1.57*time));
omega[2]=-0.411*cos(1.57*time+1.57)*cos(0.7*sin(1.57*time));
}
when i want to interpreted udf，the error appears as follows :
cpp -I"E:\Fluent.Inc\fluent6.3.26/src" -I"E:\Fluent.Inc\fluent6.3.26/cortex/src" -I"E:\Fluent.Inc\fluent6.3.26/client/src" -I"E:\Fluent.Inc\fluent6.3.26/multiport/src" -I. -DUDFCONFIG_H="<udfconfig.h>" "F:\airfoil0012-20wan'\2.c"
Error: F:\airfoil0012-20wan'\2.c: line 37: function "Compute_Force_And_Moment" not found (pc=88).
Who can tell me the reason?
thanks a million.</SPAN>