I need you help about DUF
 

hi

I want to calculate the multiphase flow .And I want to give a centripetal acceleration to particle.I must get the current position of particle.

I use "p->state.pos[1]" but the fluent show error

the follow is my program

#include "dpm.h" #include "sg.h" #include "prop.h"

#define C_acceler 30.0 /* centripetal acceleration */

DEFINE_DPM_BODY_FORCE(particle_body_force, p, i) {

real y,z; real alpha; face_t f; /* particle_state_t *c = &(p->state); */ float bforce; /* centripetal force */

y = p->state.pos[1]; /* particle y axis coordinate */ z = p->state.pos[2]; /* particle z axis coordinate */

alpha = acos(fabs(z)/(sqrt(pow(z,2)+pow(y,2))));

if(z>0)

{

if(y>0)

{

if(i==1) bforce=-C_acceler*sin(alpha)*P_MASS(p)*9.8;

else if(i==2) bforce=-C_acceler*cos(alpha)*P_MASS(p)*9.8;

}

else

{

if(i==1) bforce=C_acceler*sin(alpha)*P_MASS(p)*9.8;

else if(i==2) bforce=-C_acceler*cos(alpha)*P_MASS(p)*9.8;

}

}

else

{

if(y>0)

{

if(i==1) bforce=-C_acceler*sin(alpha)*P_MASS(p)*9.8;

else if(i==2) bforce=C_acceler*cos(alpha)*P_MASS(p)*9.8;

}

else

{

if(i==1) bforce=C_acceler*sin(alpha)*P_MASS(p)*9.8;

else if(i==2) bforce=C_acceler*cos(alpha)*P_MASS(p)*9.8;

}

}

return (bforce);

}

After Interpreted compile flunet show error " structure reference not implemneted" what's wrong wiht it ?what can I do , can you give me some advise, I hope you can help me ,thank you very much thanks

Re: I need you help about DUF
 

I'm not an expert but I see that you're lacking of

#include "udf.h"

also keep in count that the arrays in c begins in 0, so the positions are in state.pos[0],state.pos[1], state.pos[2]

Hope this helps Arturo

Re: I need you help about DUF
 

thank you I have include "udf.h" in my program, when I copy it to here ,I miss it.

I have compile the example program in UDF Use's Guide 5.4.1 "Melting Index Along a Particle Trajectory" ,it failed either.

could you help me ,if you know the reason, please tell me ,thank you

Re: I need you help about DUF
 

Weird, I have compiled the same example flawlessly. In which platform are you running? Maybe you have to check your compiler installation.

Regards

Re: I need you help about DUF
 

I use fluent 5.4 in nt4 do you use Interpreted UDFs or Compiled UDFs when you comilpe the example code.

thank you

Re: I need you help about DUF
 

I work in NT and Linux and always compile my functions, maybe that is your problem because some structures are not available in interpreted functions. Try to compile. Regards