About UDF source term
 

I'm new in Fluent. Please help me.
I recieved UDS file from my professor.
This is research about Flux model in pipe.

#define Gamma0 1.89153e-6 /* Mass Accommodation Coefficient [-] */
#define Gamma1 1.20e-6
#define Bvel 340.0 /* Boltzman Velocity [m/s] */
#define Dm 1.50e-5 /* Diffusion Coefficient [m2/s] */

In this contents, What is meaning of Mass Accommodation?
And How can i know value 1.89153e-6.

Finally, Do you know this equation?

damp1= ((Gamma0 * Bvel/4.0)/(1+Gamma0 * Bvel/4.0 * dy1/Dm ));
F_PROFILE(f, t, i) = damp1 * cy1 * (-1);

The best person to go to for a model that you received from your professor, is your professor.