[Jinming Wu]

When performing Fluent transient simulation, I encountered the problem that the Message script (with subscript) is excuted more than once in every time step, and the variable value is different every time. Does anyone know why is this happen.

The script is shown below, and the result is shown in Fig1.

Thank you for your help!


#include "udf.h"
real cvelocity[3]={0,0,0};
real rotcentroid[3]={150,0,0};
real m1=5736;

DEFINE_CG_MOTION(T1,dt,vel,omega,time,dtime)
{
Thread *thread;
Domain *domain;

real force[3]={0,0,0};
real moment[3]={0,0,0};

NV_S(vel, =, 0.0);
NV_S(omega, =, 0.0);

if(!Data_Valid_P())
return;

domain=Get_Domain(1);
thread=Lookup_Thread(domain,4);
Compute_Force_And_Moment(domain,thread,rotcentroid ,force,moment,TRUE);

cvelocity[0]+=dtime*(force[0]/m1);
cvelocity[1]+=dtime*((force[1]-m1*9.81)/m1);

vel[0]=cvelocity[0];
vel[1]=cvelocity[1];

Message("\nvel[0] equals %f\n",cvelocity[0]);
}

[Jinming Wu]

Does anyone know how tho solve this problem?