Prashanth
Ansys Employee

Hi 

I checked the docs and found that the Keff definition is already covered in VOF model's energy equation. You can check there as the definitions won't get repeated if its covered before in previous section. 

https://ansyshelp.ansys.com/account/secured?returnurl=/Views/Secured/corp/v221/en/flu_th/flu_th_sec_vof_energy.html