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Define mass flow profile with regards to species mass fraction

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Old   June 20, 2017, 07:21
Default Define mass flow profile with regards to species mass fraction
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Daniel
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Hi!

I am trying to write a UDF for defining a mass flow profile with regards to species mass fraction. I have a constant mass flow with a mass fraction of 1 for the water species at the inlet of the domain (which happens to be a porous zone) and I want to have a mass outlet which removes mass when the mass fraction of water (I have water and air as species) is above 0.1.
The UDF below compiles and runs (depending on the initial conditions), but it seams to not loop over all faces in the face thread. The counter I have in the UDF does not match the number of elements I have on my face thread. It skip about 75% of the faces I have on the thread and I don't understand why?

Also, my steady-state simulation crashes without completing 1 iteration when I initialize the domain with 0 mass fraction water, but it runs fine when I initial the domain with a mass fraction above 0.1. I can't understand why, but my understanding for UDF programming is limited so maybe someone of you might see what is wrong with my code?

#include "udf.h"

DEFINE_PROFILE(mass_flow, thread, in)
{
face_t f;
Thread *c0_thread;
cell_t c0;
int i = 0;
real counter=0.;
real A[ND_ND];

begin_f_loop(f, thread)
{
c0_thread=THREAD_T0(thread);
c0=F_C0(f,thread);
if (C_YI(c0,c0_thread,i) > 0.1)
{
F_AREA(A,f,thread);
F_PROFILE(f,thread,in) = 0.0001*(C_YI(c0,c0_thread,i)-0.1)*NV_MAG(A);
}
else
{
F_PROFILE(f,thread,in) = 0.;
}
counter=counter+1;
}
end_f_loop(f,thread);
Message("%5.15f\t\n",counter);
}

/Daniel
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