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ISSN Online: 2377-424X

ISBN Print: 978-1-56700-474-8

ISBN Online: 978-1-56700-473-1

International Heat Transfer Conference 16
August, 10-15, 2018, Beijing, China

HEAT FLUX DENSITY MEASURMENTS IN THE CONTACT LINE OF THE HEATED SESSILE DROPLET/FALLING DOWN LIQUID RIVULET

Get access (open in a dialog) DOI: 10.1615/IHTC16.mpf.024707
pages 6633-6640

Abstract

The evaporating water droplets on a horizontal heated substrate and falling down water/FC-72 liquid rivulets on a vertical heated substrate was experimentally investigated. The foil made of constantan with thickness of 25 μm and a size of 88×35 mm2 was used as a heated substrate. The experiments were carried out with a single droplet, with an ensemble of two or three droplets on the foil and also with falling down liquid rivulet on the vertical foil. With the help of an IR scanner the temperature of the lower surface of the foil was measured. The heat flux density at evaporation of liquid near the contact line is determined by solving the Cauchy problem for the heat conduction equation using the thermographic data. The maximal heat flux density takes place in the region of the contact line and exceeds significantly the heat flux density from the entire surface of the foil. This is explained by the heat transport from the foil periphery to the droplet/rivulet due to the relatively high value of the coefficient of heat conductivity of the constantan and by the high evaporation intensity in the contact line region.