[zobekenobe]

I am trying to find the amount of a user defined scalar passing through a interior edge/wall.

especially the line in bold

DEFINE_ADJUST(func_name, domain)
{
        Thread* s1 = Lookup_Thread(domain, segment1);
	Thread* t0 = s1->t0;
	face_t facet;
	cell_t c0;

	begin_f_loop(facet, s1)
	{
		c0 = F_C0(facet, s1);
		value1 	= fabs(F_FLUX(facet, s1)) * C_UDSI(c0,t0,r);
	}
	end_f_loop(facet, s1)

thanks

[mCiFlDk]

Hi zobekenobe,

Have you thought about doing it in the post-proc? I mean, create an iso-surface and measure the amount of a certain variable passing though it. In the "report" label, "fluxes" in the main fluent command menu.

Regards

[vinerm]

The value returned by the UDF will just be a field showing product of mass flow rate and scalar value. That's not the flow rate of scalar. Firstly, you need to sum over the faces. Secondly, the flow rate of the scalar depends upon the scalar's definition. E.g., if the scalar represents temperature, then you also need to multiply the product of mass flow rate and temperature with specific heat. If the scalar represents species mass fraction, then the formulation is correct. But in any case, you need to sum over the face loop. Or as suggested by mCiFlDk, you can use surface integral. Reports > Flux will not give flow rate of scalars but you can define a custom-field-function and then take its surface integral over the boundary. Again, cff depends on the type of scalar.