[swtbkim]

Hi all.

I'm writing a code for situation of particle impact on the wall.
When a particle hit the wall, if some criterion is satisfied, then particle is trapped and if not, then particle is reflected.
I want to know the mass flux of trapped particles on the wall.
So the code is written in this way:

#include "udf.h"

DEFINE_DPM_BC(BC,p,t,f,normal,dim)
{

// some calculations here //

if(force1 <= force2){

F_AREA(A,f,t);
area = NV_MAG(A);

c0 = F_C0(f,t);
t0 = THREAD_T0(t);
P_USER_REAL(p,0) = P_FLOW_RATE(p)/area;
C_UDMI(c0,t0,0) = P_FLOW_RATE(p)/area;

return PATH_ABORT;
}
else
return PATH_ACTIVE;
}

Here, the flow field converged well. That is, residual and other monitors converge to a constant, and DPM concentration at outlet also converges.
So I expected that C_UDMI(c0,t0,0) will also converge to a constant, because it is mass flux trapped at the wall and steady state solution is obtained.
But C_UDMI keeps increasing with nearly constant slope.. It looks like that C_UDMI is accumulated with the value of C_UDMI at the previous iteration!
Am I understanding right? And how can I fix this problem??
I am not good at UDF actually, so any fundamental advice will also be helpful to me.

Second question is about P_USER_REAL(p,0). I heard that I should use P_USER_REAL(p,0) for storing particle-related value when I use parallel solver.
Here, how can I see P_USER_REAL?
For example, I expect that the value of mass flux will be stored in P_USER_REAL, so I may be able to make a contour of P_USER_REAL so that I can show where particles are trapped more.
But there is no option about it in Results > Graphics > Contours > Contours of..

Any comment will be very helpful to me.

Thank you.