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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

THERMAL WAVES AT THE INTERFACE OF AN EVAPORATING LIQUID POOL

Get access (open in a dialog) DOI: 10.1615/IHTC16.bae.022748
pages 1317-1324

Sinopsis

In recent literature, the hydrothermal waves were observed at the liquid-air interface of an evaporating sessile droplet based on the thermal graphic technology. Similarly but differently, we experimentally observed a series of time-depended temperature oscillation patterns on the flat interface of an evaporating liquid pool. The evaporation required energy was purely supplied from the direction parallel to the interface by a line heater tangential to the interface. This configuration decoupled the two key contributions to the hydrothermal waves in the droplet evaporation case: the thermo-capillary flow induced by the temperature gradient parallel to the interface, and the buoyancy flow induced by the temperature gradient perpendicular to the interface. In the experiments, the evaporating liquid pool was placed in a controlled chamber which was vacuumed by a vacuum pump. The absolute pressure was kept at 800 mbar throughout the experiments. In order to establish an equilibrium state, the fresh degassed liquid was supplied by a syringe pump to the liquid pool in order to compensate the evaporated liquid. The results showed that the wavy temperature oscillation could be generated in the vicinity of the heating wire, and then the waves were travelling away from the heat source. Finally, the spatio-temporal variations of the interface temperature were reported and discussed.