Leidenfrost effect at thermodynamic equilibrium

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SUMMARY

The discussion centers on the Leidenfrost effect at thermodynamic equilibrium, specifically analyzing the pressure difference between the liquid drop and vapor phase. The participant derived the equation PL - PV = 3σ/a, where σ represents surface tension and a is the radius of the drop. This conclusion adheres to the three laws of thermodynamics and emphasizes the importance of entropy maximization in equilibrium states. The participant confirms the dimensional correctness of their result while seeking validation of their approach.

PREREQUISITES
  • Understanding of the three laws of thermodynamics
  • Knowledge of surface tension concepts
  • Familiarity with entropy maximization principles
  • Basic grasp of vapor-liquid equilibrium dynamics
NEXT STEPS
  • Study the implications of surface tension in thermodynamic systems
  • Explore advanced topics in vapor-liquid equilibrium
  • Learn about entropy calculations in isolated systems
  • Investigate the mathematical modeling of the Leidenfrost effect
USEFUL FOR

Students and researchers in thermodynamics, physicists studying phase transitions, and engineers working with heat transfer and fluid dynamics will benefit from this discussion.

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Homework Statement


A spherical drop of a pure substance floats on top of the vapor of the same substance so the system vapor+drop is isolated. The drop has a surface tension σ. Show that at the thermodynamic equilibrium PL≠PV and calculate the difference.

Homework Equations


Three laws of thermodynamics

The Attempt at a Solution


I solved this one already but I would like to check my result. Following the three laws of thermodynamics and maximizing the entropy at the equilibrium yadda yadda yadda I got PL-PV=3σ/a, where a is the radius of the drop. The dimension of the result seems correct.
 
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Is there a question here? If the question is "Am I right?", you have to supply the "yadda, yadda, yadda" so that someone can check your work and point out possible mistakes.
 
kuruman said:
Is there a question here? If the question is "Am I right?", you have to supply the "yadda, yadda, yadda" so that someone can check your work and point out possible mistakes.

Ok...
For σ=0, Thermodynamic equilibrium says: PL=PV, but if we add a work therm for the liquid -σdS=-3σdV/a we get PL-PV=3σ/a.
 

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