[dipikka89]

Hi all!

I'm trying to simulate a 2D FCC riser reactor. The 5 lump cracking reactions are incorporated through a UDF. The library is built and is not giving any error. But after running the simulation for some time, I found that the mass concentrations of all the products are the same. Given below is my UDF. Kindly check and let me know why is it not working. It would be a great help!!!

#include "udf.h"
DEFINE_VR_RATE(cracking,c,t,r,mw,species_massf,rr, rr_t)
{
double k_12, k_13, k_14, k_15, k_23, k_24, k_25, k_34, k_35, phi_12, phi_13, phi_14, phi_15, phi_23, phi_24, phi_25, phi_34, phi_35, nu_12, nu_13, nu_14, nu_15, nu_23, nu_24, nu_25, nu_34, nu_35, goil, gasoline, lpg, coke, drygas;
k_12 = 0.23;
k_13 = 0.08;
k_14 = 0.003;
k_15 = 0.031;
k_23 = 0.0016;
k_24 = 0.00022;
k_25 = 0.00008;
k_34 = 0.00;
k_35 = 0.00021;
phi_12 = 0.8795;
phi_13 = 0.8877;
phi_14 = 0.8580;
phi_15 = 0.9099;
phi_23 = 0.8877;
phi_24 = 0.8580;
phi_25 = 0.9099;
phi_34 = 0.00;
phi_35 = 0.9099;
nu_12 = mw[0]/mw[1];
nu_13 = mw[0]/mw[2];
nu_14 = mw[0]/mw[3];
nu_15 = mw[0]/mw[4];
nu_23 = mw[1]/mw[2];
nu_24 = mw[1]/mw[3];
nu_25 = mw[1]/mw[4];
nu_34 = mw[2]/mw[3];
nu_35 = mw[2]/mw[4];
goil = C_R(c,t)*species_massf[0]/mw[0];
gasoline = C_R(c,t)*species_massf[1]/mw[1];
lpg = C_R(c,t)*species_massf[2]/mw[2];
coke = C_R(c,t)*species_massf[3]/mw[3];
drygas = C_R(c,t)*species_massf[4]/mw[4];
if (!strcmp(r->name, "reaction-1"))
{
*rr = (1.-C_VOF(c,t))*-((k_12*phi_12+k_13*phi_13+k_14*phi_14+k_15*phi_15) *(pow(goil,2)));
}
else if (!strcmp(r->name, "reaction-2"))
{
*rr = (1.-C_VOF(c,t))*(((nu_12*k_12*phi_12)*(pow(goil,2)))-((k_23*phi_23+k_24*phi_24+k_25*phi_25)*goil));
}
else if (!strcmp(r->name, "reaction-3"))
{
*rr = (1.-C_VOF(c,t))*(((nu_13*k_13*phi_13)*(pow(goil,2)))+( nu_23*k_23*phi_23*gasoline)-((k_34*phi_34+k_35*phi_35)*lpg));
}
else if (!strcmp(r->name, "reaction-4"))
{
*rr = (1.-C_VOF(c,t))*(((nu_14*k_14*phi_14)*(pow(goil,2)))+( nu_24*k_24*phi_24*gasoline)+(nu_34*k_34*phi_34*lpg ));
}
else if (!strcmp(r->name, "reaction-5"))
{
*rr = (1.-C_VOF(c,t))*(((nu_15*k_15*phi_15)*(pow(goil,2)))+( nu_25*k_25*phi_25*gasoline)-(nu_35*k_35*phi_35*lpg));
}
}