[jeniuswx]

hey！i am modelling the surface reaction，the overal reaction equation：2O3 -> 3O2. and its reaction rate formular is: r = K*b*O3/(1+b*O3); my UDF code as follows：
#include "udf.h"
#define K 6.8586e-11
#define b 15296.9e3
DEFINE_SR_RATE(my_rate,f,t,r,mw,yi,rr)
{
Thread *t0 = t->t0;
cell_t c0 = F_C0(f,t);
real o3 = yi[0];
real rho_w = 1.0, T_w = 300.0;
T_w = F_T(f,t);
rho_w = C_R(c0,t0)*C_T(c0,t0)/T_w;
o3 *=rho_w/mw[0];
*rr = K*b*o3/(1+b*o3);
}

the problem is：after compile and hook the UDF，the calcucation results showed that the reaction rate on the defined surface was zero。is there anyone who can help me analyse where the problem is and how to solve it? thanks!

[sebastian1430]

Good afternoon, excuse me, did you find a solution to your problem? I’m experiencing the same; I would appreciate greatly your help.

[sjkim]

Originally Posted by jeniuswx

hey！i am modelling the surface reaction，the overal reaction equation：2O3 -> 3O2. and its reaction rate formular is: r = K*b*O3/(1+b*O3); my UDF code as follows：
#include "udf.h"
#define K 6.8586e-11
#define b 15296.9e3
DEFINE_SR_RATE(my_rate,f,t,r,mw,yi,rr)
{
Thread *t0 = t->t0;
cell_t c0 = F_C0(f,t);
real o3 = yi[0];
real rho_w = 1.0, T_w = 300.0;
T_w = F_T(f,t);
rho_w = C_R(c0,t0)*C_T(c0,t0)/T_w;
o3 *=rho_w/mw[0];
*rr = K*b*o3/(1+b*o3);
}

the problem is：after compile and hook the UDF，the calcucation results showed that the reaction rate on the defined surface was zero。is there anyone who can help me analyse where the problem is and how to solve it? thanks!

I think that the problems may be in the definition of yi[] and mw[].
You must check the order of species in your mixture-template.