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ISSN Online: 2377-424X

ISBN Print: 0-89116-299-2

International Heat Transfer Conference 7
September, 6-10, 1982, Munich, Germany

RIVULET FORMATION ON A HEATED WALL

Get access (open in a dialog) DOI: 10.1615/IHTC7.1220
pages 363-368

Abstract

A catastrophe theory is developed for breakdown of a falling liquid film under heating and surface shear stress, which combines elements of small-perturbation and rivulet theories. In doing so the critical effects of both thermocapillary effects and contact angle are combined for the first time into a single theory starting with a small surface wave. The theoretical difficulties previously encountered with spatially-growing wave models for dryout are obviated by assuming a time-dependent "roping" instability, in accord with experimental observations. The theory takes into account also surface shear stress. Agreement with minimum thickness data for water and Freon evaporating films is satisfactory, but a single set of data for subcooled water films is underpredicted by a factor of two. Some speculations are given for the underestimation of the thermocapillary effect by the linear theory, but additional data will be required to resolve these questions.