Evaporation-induced Benard convection -- A new type and its mechanism
Both the buoyancy-induced (Rayleigh-Bernard) and surface tension-induced (Marangoni-Benard) convection require a negative temperature gradient to occur in a thin liquid layer, either heated from below or cooled from above. This study has revealed an entirely different way of bringing about cellular convection in a thin liquid layer with evaporation at the free surface and cooled, adiabatic or heated from below. Temperature-time history is monitored in the liquid layer and its adjacent atmospheric environment. Flow visualization is conducted by means of the tracer method and results are compared with those obtained in the existing literature using an optical technique. Various different liquids are tested including those classified as stable, unstable, unstable types in the study of convection phenomena in a sessile droplet evaporating on a plate. It is disclosed from the study that evaporation at the free surface of a thin liquid layer results in a negative temperature gradient in the upper stratum in which cellular convection may occur irrespective of a positive, zero, or negative temperature gradient prevailing in the remaining lower stratum.
- Research Organization:
- Univ. of Michigan, Ann Arbor, MI (US)
- OSTI ID:
- 20014422
- Resource Relation:
- Conference: 32nd National Heat Transfer Conference, Baltimore, MD (US), 08/08/1997--08/12/1997; Other Information: PBD: 1997; Related Information: In: ASME proceedings of the 32nd national heat transfer conference (HTD-Vol. 349). Volume 11: Interfacial thermal phenomena in thin films; Heat pipes and thermosyphons; Heat and mass transfer in porous media, by Goodson, K.; Chang, W.S.; Charmchi, M.; Hadim, H. [eds.], 211 pages.
- Country of Publication:
- United States
- Language:
- English
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