[Laexzzz]

Im trying to model chem. reaction.

I used volumetric reaction laminar finite rate mechanism

I0 => 2R0 (rate constant for 333K is 8.28971E-06)

Then i made UDF function

#include "udf.h"

DEFINE_SOURCE(I0_source,c,t,dS,eqn)
{

real I0_source;
real Dens = C_R(c,t);
real I0MC;
real I0MC_source;

I0MC = (C_YI(c,t,0)*Dens) / 164;
I0MC_source = -8.28971E-06*I0MC;
I0_source = I0MC_source*164;
dS[eqn] = 0;
return I0_source;
}

DEFINE_SOURCE(R0_source,c,t,dS,eqn)
{

real R0_source;
real Dens1 = C_R(c,t);
real I0MC1;
real R0MC_source;

I0MC1 = (C_YI(c,t,0)*Dens1) / 164;
R0MC_source = 2*8.28971E-06*I0MC1;
R0_source = R0MC_source*82;
dS[eqn] = 0;
return R0_source;
}


But there is a big difference between results of this 2 cases.





Any ideas?

Boundary condition are identical