Nonlinear mass and heat transfer across liquid-vapor interfaces

Area of Science:

• Thermodynamics
• Kinetic Theory
• Fluid Dynamics

Background:

• Mass and heat transfer across liquid-vapor interfaces are fundamental in many physical processes.
• Existing models often simplify interface phenomena, neglecting nonlinear effects.
• Irreversible thermodynamics and kinetic theory provide frameworks for understanding these transfers.

Purpose of the Study:

• To develop a nonlinear extension of the Hertz-Knudsen-Schrage (HKS) model for mass and heat transfer across liquid-vapor interfaces.
• To link this extended model to the force-flux relations of nonequilibrium thermodynamics.
• To investigate the dependence of interface resistivities on temperature, mass flux, and heat flux.

Main Methods:

• Extension of the Hertz-Knudsen-Schrage (HKS) model to incorporate nonlinearities.
• Formulation of a corresponding heat transfer relation.
• Determination of nonlinear interface resistivities within the framework of nonequilibrium thermodynamics.
• Nondimensionalization of resistivities using temperature and saturation pressure.

Main Results:

• The extended HKS model shows good agreement with established kinetic theory for zero heat flux conditions.
• Interface resistivities were found to depend on interface temperature, mass flux, and heat flux.
• Nondimensionalized resistivities were shown to be independent of local temperature.
• Reevaluation of Molecular Dynamics data confirmed distinct nonlinearities in interface resistivities.

Conclusions:

• The nonlinear extension of the HKS model provides a more accurate description of interfacial mass and heat transfer.
• Interface resistivities exhibit significant nonlinear behavior, dependent on flux conditions.
• The findings contribute to a deeper understanding of nonequilibrium phenomena at liquid-vapor interfaces.