[hadesmajesty]

Hi, I am trying to implement a pressure outlet boundary condition by UDF in fluent.
The model is 3D and this boundary condition involves the pressure and inlet flux at last time step. I meet some problem in my implementation, especially how to store the previous pressure and flux. Below is part of the code:
DEFINE_PROFILE(pressure_wk_profile,t,i) //t means thread
{

sumFlow = 0;//total flux at inlet current time step
sumFlow_M1 = 0;// for previous time step
tot_vol = 0;// total volume
p_M1 = 0; //pressure at last time step


begin_f_loop(f, t)
{ //…
sumFlow = sumFlow + F_FLUX(f,t); //calculate total mass flow rate.
//I am not sure what F_FLUX return is the inlet flux or previous outlet flux.
c0 = F_C0(f, t);
t0 = THREAD_T0(t);
tot_vol = tot_vol + C_VOLUME(c0,t0);
sumFlow_M1 = sumFlow_M1 + C_UDMI(c0,t0,1);//
p_M1 = p_M1 + C_UDMI(c0,t0,0)*C_VOLUME(c0,t0);
//It seems not work, and is there any simpler way to store/visit pressure at last step?
}
end_f_loop(f, t)
p_M1 = p_M1 / tot_vol;

begin_f_loop(f, t)
{
F_PROFILE(f,t,i) = somefunction(p_M1, sumFlow, sumFlow_M1);
}
end_f_loop(f,t)
}

DEFINE_EXECUTE_AT_END(execute_at_end)
{
Domain *d;
Thread *t, *t0;
cell_t c, c0;
face_t f;
real tt;
d = Get_Domain(1);
thread_loop_c(t,d)
{
begin_c_loop(c,t)
C_UDMI(c,t,0) = C_P(c,t);
end_c_loop(c,t)
}

thread_loop_f(t,d)
{
begin_f_loop(f,t)
{
c0 = F_C0(f, t);
t0 = THREAD_T0(t);
C_UDMI(c0, t0, 1) = F_FLUX(f,t); //store flux at each face
}
end_f_loop(f,t)
}
}

[blackmask]

Not sure what you want but try C_P_M1(c,t) if you want to retrieve the pressure in previous time step for a given cell c and thread t.