I am modelling a screen mesh heat pipe.We know that the effective thermal conductivity of a screen mesh wick is given by

Kl( (Kl+Kw) - (1-e)(Kl-Kw)) /( (Kl+Kw) +(1-e)(Kl-Kw))

where Kl and Kw are the thermal conductivities of working fluid and wick material.'e' is the porosity of wick.

My question -What is the expression for thermal conductivity when the screen mesh wick is partially saturated and when screen mesh is completely dry ?