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ISSN Online: 2377-424X

International Heat Transfer Conference 12
August, 18-23, 2002, Grenoble, France

Experimental Determination of the Leidenfrost Transition for Water and Aqueous Liquid Mixtures

Get access (open in a dialog) DOI: 10.1615/IHTC12.2360
6 pages

Аннотация

This paper summarizes the results of experiments in which the Leidenfrost transition conditions were determined for pure water and a aqueous solutions at atmospheric pressure. These experiments determined Leidenfrost conditions for liquid deposited in fixed volumes on a hot aluminum surface. The experiments specifically focused on aqueous solution at low additive concentration levels for a surface-active alcohol (propanol) that reduces the interfacial tension and increase the vapor pressure. In this investigation, in tandem with more traditional temperature and heat transfer measurements, we explored the use of acoustic recordingin strumentation was to characterize the degree of liquid contact with the solid surface. The results provide insight into the mechanisms of the Leidenfrost transition. Traditionally, this transition has been interpreted as the incipient collapse of the vapor film separatingt he liquid-vapor interface from the solid surface. Experiments indicate that for pure water and aqueous mixtures of the sort considered here, the transition may occur in stages. At very high surface temperatures, the vapor film prevents any liquid contact with the solid. At lower temperatures, the liquid fully wets the surface. At intermediate temperatures, intermittent periods of stable vapor film formation are punctuated by intervals of film collapse and rewetting. Results for pure water and mixtures are summarized and compared to Leidenfrost temperature predictions developed in previous investigations.