What is really SGS dissipation term in LES?
 

Dear all friend

I am a new one in the field of LES modeling and got confused by some basic definitions!
I am trying to modified KIVA with smagorinsky and k-delta one equation SGS turbulent kinetic energy. As you may be aware, kiva use internal equation energy rather that total energy conservation. so by using filter form of internal energy the terms of SGS viscous dissipation appears. and also by using the filter operation in turbulent kinetic energy equation to produce SGS turbulent kinetic energy, the term of SGS kinetic energy dissipation appears.

I've got some question here!
1- sorry for this question from a very beginner in turbulence, what is a real different between SGS viscous dissipation and SGS turbulent kinetic energy dissipation?
2- why in some literature by using k-delta model, both SGS viscous dissipation and SGS turbulent kinetic energy dissipation are modeled by one functional equation? does is mean that they are the same?
3- As i think it is not necessary to solve SGS turbulent kinetic energy in smagorisnky model, how are we able to model SGS viscous dissipation?