[sarah l]

Hi,
i want to define thermal conductivity according to Zehner and Schluender correlation;




I wrote the following Udf but it doesn't work!
#include "udf.h"
DEFINE_PROPERTY(ksolid,c,t)
{
real ktc;
real temp= C_T(c,t);
real por;
real e_r;
real k_g;
real a;
real b_z;
real sigma;
por=0.36;
e_r=0.8;
sigma=0.0000000567;
b_z=1.25*pow(((1.-por)/por),1.11);
k_g=156.97-0.0988*temp+2.083e-05*pow(temp,3);
a=k_g/0.24*sigma*pow(temp,3.);
ktc=0.24*sigma*pow(temp,3.)*((1.-pow((1-por),0.5)+(((pow((1-por),0.5)/(2.*pow(e_r,-1.)-1.))*((b_z+1.)/b_z)*pow((1+(1/((2.*pow(e_r,-1.)-1)*a))),-1.),
return ktc;
}

is there any one to help me????