[mingersai]

Hi, friends

I want to define a mass source on the boundary cells with udf, here's my code,
I don't know why it doesn't work, can any of you guys kindly give me some suggestions?
I'm new to udf...

Thanks in advance!

# include "udf.h"

DEFINE_SOURCE(mass_source,c,t,dS,eqn)
{
real x[ND_ND];
real source;
Domain *domain = Get_Domain(1);
face_t f;
Thread *tb = Lookup_Thread(domain,2); /* Get boundary thread, wall zone id is 2 */
if(c = F_C0(f,tb)) /* if cell is wall boundary cell */
{
source = 10000;
dS[eqn]=0;
}
else
{
source = 0;
dS[eqn]=0;
}
return source;
}

Thank you very much!