problem with UDF

Nina

Hi All, I've problem with an UDF. I have to define a pressure profile that respond to the following equation: ((Ql*Ri)+(vol/C)) where Ql is the flow rate at the current time, Ri and C are costant and vol derive to the following expression ((Ql*(current time-previous time))+volume at the previous time). I've made different UDF where I've used the variables F_U, F_V, F_W e F_U_M1, F_V_M1, F_W_M1 but I'm not an expert so maybe I've missed something because UDF doesn't run well. I've tried also with some external variables but I don't understand how I've to use them…I'm really hopeless!! This is the UDF: DEFINE_PROFILE(press_insp,thread,position)

{

face_t f;

real NV_VEC(psi);

real NV_VEC(A);

real NV_VEC(psit);

real intervallo =0.0;

real ora = 0.0;

real prima = 0.0;

real Q=0;

real Ql=0;

real vol=0;

real Qtl=0;

real volprec=0;

real Qt=0;

ora=CURRENT_TIME;

prima=PREVIOUS_TIME;

intervallo=ora-prima;

begin_f_loop(f,thread)

{

F_AREA(A,f,thread);

NV_D(psi,=,F_U(f,thread),F_V(f,thread),F_W(f,threa d));

Q=NV_DOT(psi,A);

Ql= Q*1000;

NV_D(psit,=,F_U_M1(f,thread),F_V_M1(f,thread),F_W_ M1(f,thread));

Qt=NV_DOT(psit,A);

Qtl=Qt*1000;

volprec=Qtl*intervallo;

vol=((Ql*intervallo)+volprec);

intervallo = istante - precedente;

F_PROFILE(f,thread,position)=((Q/C)+(((Q-Qt)/intervallo)*Ri));

}

end_f_loop(f,thread)

}