[Peter_Beshay]

Hi,
I am very new in UDF and do not have much knowledge on C.
I need urgent help in a UDF to:
1- specify the porous zone ID
2- read the particle concentration in each cell
3- reduce it as a percentage from the initial concentration
4- store the new reduced concentration

I tried for many days but i am stuck, i really appreciate if anyone will help me.
The code i tried is below (probably it is very bad):

#include "udf.h"
#include "sg_mem.h"
# include "dpm.h"
# define domain_ID 4
DEFINE_ADJUST(adjust_UDS,domain)
{
Thread *t;
cell_t c;
domain = Get_Domain(domain_ID);
/*Fill UDS with the variable*/
thread_loop_c (t,domain)
{
begin_c_loop (c,t)
{
C_UDSI(c,t,0) = C_DPMS_CONCENTRATION(c,t);
}
end_c_loop (c,t)
}
}
DEFINE_SOURCE(conc_source,c,t,dS,equ)
{
real x[ND_ND],c_source;
source= (C_UDSI(c,t,0) + C_UDSI(c,t,0));
return source;
}