DEFIND_SOURCE with looping through DPM particles
 

help!

I run a simulation with Discrete Phase model. The Defind_Source macro is used for the continuity, and I want to relate it with DPM particles, so how to write the UDF with Looping over the particles in the cell?

Hi,
Loop over all particles and check whether it is in your desired cell and thread or not with P_CELL and P_THREAD commands:

dear Amir, many thanks for your reply.
A main difficult to loop over all particles in Define_Source macro is that I can't get the tracked particle thread.
My test UDF is as following:

# include "udf.h"
DEFINE_SOURCE(chg_source,c,t,dS,eqn)
{
int I=0;
real xc[ND_ND];
real source;

Tracked_Particle *p;
cell_t cell;

loop(p,I->p)
{
cell = P_CELL(p);
if (c==cell)
{
C_CENTROID(xc,c,t);
Message("P_POS(p)[0]: %g\n", P_POS(p)[0]);
Message("P_POS(p)[1]: %g\n", P_POS(p)[1]);
Message("xc[0]: %g\n", xc[0]);
Message("xc[1]: %g\n", xc[1]);
}
dS[eqn] = 0;
source = 0;
return source;
}

compiling Error is in line: loop(p,I->p)

Hi,

First of all, I don't think "I" is defined properly, is it integer?! But I think if there would be a problem in this procedure, it's better to change order of loops; i.e., use a DPM macro which automatically have a loop over particles; maybe "SCALAR_UPDATE" is proper; then store effect of each particle in its temporary cell memories and then use that memory in your source macro. I can elaborate it more if it's not clear.

Bests,

it's a good idea. I'll try it. thanks for your advice.