DEFINE_SOURCE - Problem
 

Hello,
I'm trying to write a UDF for an laminar duct flow that effects the fluid like there is a semi-high wall in the middle. This is what i have:

#include "udf.h"

DEFINE_SOURCE(xmom,cell,thread,dS,eqn)
{
real source, CON = 10000.0;
face_t f;
Domain *domain;
domain = Get_Domain(1);

int zone_ID = 12;
Thread *rand = Lookup_Thread(domain,zone_ID);

begin_f_loop(f, rand)
{
source=-CON*C_U(cell,thread);
/* dS[eqn]=-CON; */
}
end_f_loop(f, rand)
return source;
}

Zone 12 is a wall which is adjusted on interior.
But the UDF is not working the way it should.
What's my fault.

Thanks

Hi,
your UDF has some logical errors.
you loop over faces of your thread and then include source to the whole domain!!!
you have to separate a zone near the plate and include source to that.

Thanks for your reply, I understand what you mean, so I implement a if-else-condition, but what can I use as condition, or how can I realise that the flow is just influenced at that position?

As I said before, you have permission to add source terms to cells, so separate a zone near your area and then hook the UDF over separated zone in boundary condition panel.

Got it, thanks a lot