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Gas spreading on a heated wall wetted by liquid
Y Garrabos1, C Lecoutre-Chabot, J Hegseth
1CNRS-ESEME, Institut de Chimie de la Matière Condensée de Bordeaux, Université de Bordeaux I, Avenue du Dr. Schweitzer, F-33608 Pessac Cedex, France.
Physical Review. E, Statistical, Nonlinear, and Soft Matter Physics
|December 12, 2001
Summary
Under weightlessness, heating a fluid near its critical point causes the gas phase to spread over hot surfaces, altering the gas-liquid interface. This phenomenon is linked to vapor recoil forces and aids understanding of boiling crisis.
Area of Science:
- Thermodynamics
- Fluid Dynamics
- Materials Science
Background:
- Near critical fluids exhibit unique phase behavior.
- Equilibrium conditions show liquid wetting and gas film separation from surfaces.
- Understanding non-equilibrium effects is crucial for advanced heat transfer.
Purpose of the Study:
- Investigate the gas-liquid interface behavior of a near-critical fluid under weightlessness and heating.
- Explain the observed changes in interface shape and apparent contact angle.
- Relate experimental findings to the phenomenon of boiling crisis.
Main Methods:
- Experiments conducted on a pure fluid slightly below its critical temperature and near critical density.
- Utilized weightlessness conditions to observe fluid behavior.
- Analyzed the influence of heating on the gas-liquid interface and apparent contact angle.
Main Results:
- Observed the gas phase spreading over a hot solid surface.
- Measured an apparent contact angle greater than 90 degrees.
- Demonstrated the fluid's sensitivity to differential vapor recoil force.
Conclusions:
- The observed gas spreading is explained by non-equilibrium effects, specifically differential vapor recoil.
- These findings provide insights into the mechanisms underlying the boiling crisis.
- The study highlights the importance of non-equilibrium thermodynamics in heat exchange processes.