Heat transfer equation in cfdemSolverPisoScalar

Hi,

I'm using cfdemSolverPisoScalar for solving the convection equation between particles and air. I'd like to know what equation is being implemented by this solver. In the documentation it was mentioned that the equation was implemented according to Nield & Bejan, Convection in Porous Media.

Can anyone direct me of the exact way it was implemented? I want to know how the heat transfer is being calculated from the air to particles. Is it based on the Li and Mason model or something else?

Can anyone help me understanding it.

Thank you very much!!
Yesaswi