[angel_97]

hello guys, i'm running this udf and i want to find the minimum distance of the particle respect to the wall. but when i print the value in the console are printed nall the values and not the minimum. someone can help me?
/* UDF adding an external body force to the particles */
#include "udf.h"
#include "dpm.h"
#include "dpm_mem.h"
#include "surf.h"
DEFINE_DPM_BODY_FORCE(particle_body_force, p, i)
{
/* declaration of variables */
double w, Dh, Ufx, Ufy, Ufz, Gx, rho, a, F_L, c_height, c_length,
c_volume, side, H, W, f_height_total, Renx, Reny, Renz, crDh, mu, aUfx, aUfy, aUfz, C1, C2, C3, C4, C_Ly, C_Lz, z, y, distancewall;
int ID=9;
real xw[ND_ND];
real vec[ND_ND];
Domain* d;
cell_t c;
Thread* t;
face_t f; //f is the face index that is inside the face thread t(our wall). You will extract the face area vector from f index
d = Get_Domain(1);
c = P_CELL(p); //cell in witch the particle is currently in
t = Lookup_Thread(d,ID); //9 is the ID number of the upper wall. t is the thread index(pointer) of the wall boundary surface 9
distancewall=100; //i'm setting an generic initial value
begin_f_loop(f,t)
{
F_CENTROID(xw,f,t); //center of each face
NV_VV(vec,=,xw,-,P_POS(p)); //vector connecting the particle to the face center that is placed at the wall. The NV_VV do the operation between 2 vectors vec=xw-P_POS(p))
//now you want to calculate the minimum distance between particle and wall, and so you want to find the minimum of the vector vec doing the loop over all the boundary face
if(distancewall>=NV_MAG(vec))
{
distancewall=NV_MAG(vec);
}
}
end_f_loop(f, t)
Message0("the wall distance is: %g\n", distancewall);
return 0;
}

[ghorrocks]

Wrong forum - try the Fluent UDF forum.