Thank you Rob,

I started with Ergun's equation and considered soil to be a mix of Sand, Silt and Clay spherical particles. By that I calculated coefficients to start with.

For viscous resistance the values are 2e+9 and for inertial rsistance are 4e+4.

For Non-equilibrium Thermal model and by taking weighted average for components, I calculated Interfacial Area Density as around 6e+5 [1/m].

Do you think these values can be used to start with? (I am asking to just make sure they are not out of scope and currently do not expect them to be accurate.)

And also about Heat Transfer Coefficient under Non-equilibrium tab, do you have any comment/advice on how I could calculate that as well?