Abo Bibliothek: Guest

ISSN Online: 2377-424X

ISBN Print: 1-56032-797-9

International Heat Transfer Conference 11
August, 23-28, 1998, Kyongju, Korea

MICRO-TRANSPORT PHENOMENA IN THE WORLD OF MINUTE DROPLETS

Get access (open in a dialog) DOI: 10.1615/IHTC11.2730
pages 223-238

Abstrakt

A minute droplet represents a small world of liquids in which all kinds of transport phenomena take place as in the ordinary world, but micro in scale. A series of studies, both experimental and theoretical, were performed over two decades on micro transport phenomenal in sessile droplets. This study summarized the findings from these studies which cover natural convection in sessile droplets evaporating on an unheated surface, nucleate/transition/film boiling inside droplets on a heated surface, including the effects of the Weber number, and solidification inside droplets placed on a cooled surface. Various optical methods such as shadowgraphy, schlieren and interferometry with the aid of image processing are applied to visualize convective patterns and stability (inside droplets evaporating on an unheated surface), miniaturization phenomena (in the boiling of droplets on a heated surface) and solidification front movement (inside droplets on a cooled surface). Heat fluxes and temperature distributions are measured and the mechanisms of enhancement in transport performance are determined, especially the role of thermocapillarity. Results provide an insight into the new territory of micro transport phenomena and are applicable to the normal as well as reduced-gravity conditions.