Particle Tracking
 

Hellow everybody,

I'm trying to develop a simple model to implement on the wall conditions. My idea is quite simple. I would like to get the velocity, position (X, Y, Z) and diameter of the particle the reaches all the wall boundary condition in my domain.

Thinking about it I 'm using the DEFINE_DPM_BC to get those values export to a file and abort the trajectory of the particle.

Here I post the simple UDF that I did to compile and export the values for a single injection.

#include "udf.h"

DEFINE_DPM_BC(bc_leitura_imp, p, t, f, f_normal, dim)

{ real vx, px; real vy, py; real vz, pz; FILE *fp;

vx=P_VEL(p)[0] ;

vy=P_VEL(p)[1] ;

vz=P_VEL(p)[2] ;

px=P_POS(p)[0] ;

py=P_POS(p)[1] ;

pz=P_POS(p)[2] ;

fp = fopen("teste_export.txt","a+");

fprintf(fp,"Vel X %f\n", vx);

fprintf(fp, "Vel Y %f\n", vy);

fprintf(fp, "Vel Z %f\n", vz);

fprintf(fp,"Pos X %f\n", px);

fprintf(fp, "Pos Y %f\n", py);

fprintf(fp, "Pos Z %f\n", pz);

fclose(fp);

return PATH_ABORT; }

Now I'm trying to improve that code to do the same with a group of particle. So I would like to have the positions, velocities and so on of all the particles that reaches the wall bounday condition. To make it possible I used the GROUP injection type.

But the code above doesn't work anymore. I made some changes. I thought that would be necessary to have a loop around all the cells in the wall face making use of the code below.

#include "udf.h"

DEFINE_DPM_BC(bc_leitura_imp, p, t, f, f_normal, dim) { real vx, px; real vy, py; real vz, pz; cell_t c ; FILE *fp;

begin_c_loop (c,t) {

Particle *pi;

begin_particle_cell_loop (pi,c,t)

{

vx=pi->state.V[0] ;

vy=pi->state.V[1] ;

vz=pi->state.V[2] ;

px=pi->state.pos[0] ;

py=pi->state.pos[1] ;

pz=pi->state.pos[2] ;

fp = fopen("teste_export.txt","a+");

fprintf(fp,"Vel X %f\n", vx);

fprintf(fp, "Vel Y %f\n", vy);

fprintf(fp, "Vel Z %f\n", vz);

fprintf(fp,"Pos X %f\n", px);

fprintf(fp, "Pos Y %f\n", py);

fprintf(fp, "Pos Z %f\n", pz);

fclose(fp);

}

end_particle_cell_loop (pi,c,t) } end_c_loop (c,t)

return PATH_ABORT; }

And it didn't work. The error log is 'int' differs in levels of indirection from 'struct thread_struct *' error LNK2001: unresolved external symbol _RP_THREAD error LNK2001: unresolved external symbol _RP_CELL

Does anybody have tryed something like this before??

Thanks

Lourival

Re: Particle Tracking
 

As a new user I discovered that the first UDF was correct and it wasn't necessary to creat loop and those things.

If I want to print or acess variables for each particle in the stream just

vx=p->state.V[0] ;

vy=p->state.V[1] ;

vz=p->state.V[2] ;

px=p->state.pos[0] ;

py=p->state.pos[1] ;

pz=p->state.pos[2] ;

fp = fopen("teste_export.txt","a+"); /* Cria um arquivo para escrever e associa com fp*/

fprintf(fp,"Vel X %f\n", vx);

fprintf(fp, "Vel Y %f\n", vy);

fprintf(fp, "Vel Z %f\n", vz);

fprintf(fp,"Pos X %f\n", px);

fprintf(fp, "Pos Y %f\n", py);

fprintf(fp, "Pos Z %f\n", pz);

fclose(fp);

return PATH_ABORT;

And after the FLUENT has reached the convergence goes to the Display -> Particle Tracks -> Select the injection and click on Display, that we will get the information about all the particles in the group.