[tsi07]

Hello,
I try to make a udf which store the wall shear. But it gives zero as value. I don't understand why.

I have a 2D system.
Can anyone helps me ?

Here is the code :

# include "mem.h"
# include "udf.h"


DEFINE_ON_DEMAND(store_wall_shear)
{
	Domain *domain;
	Thread *t;
	face_t f;
	domain = Get_Domain(1);
	t=Lookup_Thread(domain,5); /* 5 is the wall in my case */
	begin_f_loop(f,t)
	{
		F_UDMI(f,t,0)=F_STORAGE_R_N3V(f,t,SV_WALL_SHEAR)[0];
		F_UDMI(f,t,1)=F_STORAGE_R_N3V(f,t,SV_WALL_SHEAR)[1];
	}
	end_f_loop(f,t)
}

Thanks

[Daniel Tanner]

Search the site for this, it has been detailed before.
If memory serves you cannot use F_UDMI() you need to use C_UDMI(). You will need to update the UDF to loop over cells.

[tsi07]

Thank you Daniel Tanner,

I have seen your previous post on the subject (here) but I had thought that it could be different with the wall shear, because it's a face data.

But finally it's the same thing.

# include "mem.h"
# include "udf.h"


DEFINE_ON_DEMAND(store_wall_shear)
{
	Domain *domain;
	Thread *t, *ct, *t0;
	face_t f;
	cell_t c, c0;
	domain = Get_Domain(1);
	t=Lookup_Thread(domain,5);
	thread_loop_c(ct, domain)
	{
		begin_c_loop(c,ct)
		{
			C_UDMI(c,ct,0) = 0.0;
			C_UDMI(c,ct,1) = 0.0;
		}
	end_c_loop(c,ct)
	}
	begin_f_loop(f,t)
	{
		c0 = F_C0(f, t);
		t0 = THREAD_T0(t);
		C_UDMI(c0,t0,0)=F_STORAGE_R_N3V(f,t,SV_WALL_SHEAR)[0];
		C_UDMI(c0,t0,1)=F_STORAGE_R_N3V(f,t,SV_WALL_SHEAR)[1];
	}
	end_f_loop(f,t)
}