Integral relations for the surface transfer coefficients

TL;DR

This paper derives relations linking local interfacial resistivities to overall surface resistances in heat and mass transfer, highlighting the significant impact of enthalpy profiles on interfacial resistances.

Contribution

It introduces new integral relations connecting local resistivities within the interface to overall resistances, emphasizing the role of enthalpy variation.

Findings

Interfacial resistances are substantially influenced by enthalpy profiles.

Surface resistances to heat and mass transfer are much higher than in homogeneous phases.

Cross effects like thermal diffusion are also affected by interfacial resistivities.

Abstract

In this paper we derive relations between the local resistivities inside the interfacial region and the overall resistances of the surface between two phases for a mixture. These resistivities are the coefficients in the force-flux relations for the stationary heat and mass transfer through the interface. We have shown that interfacial resistances depend among other things on the enthalpy profile across the interface. Since this variation is substantial (the enthalpy of evaporation is one of the main differences between liquid and vapor phases) the interfacial resistivities are also substantial. Particularly, surface put up much more resistance to the heat and mass transfer then the homogeneous phase. This is the case not only for the pure heat conduction and diffusion but also for the cross effects like thermal diffusion.