On paradoxical phenomena during evaporation and condensation between two parallel plates

Area of Science:

• Thermodynamics
• Fluid Dynamics
• Heat Transfer

Background:

• Kinetic theory predicts vapor-phase temperature inversion during evaporation and condensation between parallel plates.
• Previous studies overlooked liquid-phase transport, limiting the practical application of kinetic theory in heat transfer models.
• A disconnect exists between theoretical predictions and practical heat transfer models due to neglected liquid phase phenomena.

Purpose of the Study:

• To combine interfacial mass and heat flux conditions with continuum descriptions for vapor and liquid phases.
• To obtain a complete understanding of evaporation and condensation between parallel plates.
• To analytically rederive the criterion for temperature inversion and explain interfacial temperature jumps.

Main Methods:

• Integration of interfacial mass and heat flux conditions with continuum models for bulk vapor and liquid phases.
• Analytical derivation of the temperature inversion criterion.
• Analysis of interfacial cooling and heating processes to explain temperature jumps.

Main Results:

• The temperature jump at each interface aligns with the externally applied temperature difference.
• Interfacial cooling and heating processes explain temperature inversion, potentially leading to vapor temperatures outside the imposed wall temperature range.
• Evaporation and condensation can occur against the temperature gradient when the latent heat of evaporation is small.

Conclusions:

• The study provides a comprehensive model for evaporation and condensation between parallel plates, including liquid phase transport.
• Temperature inversion and interfacial temperature jumps are explained through interfacial energy dynamics.
• The findings challenge conventional heat transfer assumptions and offer new perspectives for practical applications.