Inverse Leidenfrost Phenomenon

Leidenfrost Dynamics

“…If a hot (smooth) object is immersed in a liquid with a much lower boiling temperature, it similarly can be surrounded by a layer of vapor. This inverse Leidenfrost effect was first described by Faraday (1828), and more recently by Hall et al (1969), by Fletcher & Thyagaraja (1989), and by Vakarelski et al (2011). It is visible in Figure 3a, which shows a centimeter-size steel ball initially at T S = 250 • C immersed (and maintained magnetically) in a liquid called FC-72 (mainly perfluorohexane) at 25 • C. The boiling point of FC-72 is 56 • C, and a vapor film (of typical thickness 100 μm) is clearly visible around the ball, producing bubbles at the upper pole (Vakarelski et al 2011).…”

THERMOHYDRODYNAMIC MODEL FOR MOLTEN UO$sub 2$--Na INTERACTION, PERTAINING TO FAST-REACTOR FUEL-FAILURE ACCIDENTS.

“…Likewise, the assumption that the vaporization process occurs as some combination of Leidenfrost, transition, and/or nucleate boiling during the intermittent contact between fuel and liquid necessitates that only a fraction of the total fuel that actually enters the mixing zone interacts at any instant of time. Support for this assumption of intermittent contact is given by recent observation of hot metal particles being suspended above a cool liquid surface by vapor generation, the effect being referred to as the inverse Leidenfrost phenomenon, 77 analogous to the well-known effect of a liquid droplet being suspended above a hot surface. 78 The observations were made by heating metal foils under water with a laser beam.…”

“…Hall et^ cil_. 77 believe that such a phenomenon might occur during the thermal interaction of high temperature debris with liquid. Although the model presented here assumes that both liquid and fuel intermittently collide with one another within an expanding vapor bubble, the point is that only a fraction of the total fuel which may be released from a failed pin interacts at any instant of time.…”

Spontaneous rotation of an ice disk while melting on a solid plate

“…The energy can be also provided by the condensed phase (the droplet or the dry ice piece); this is the so-called inverse Leidenfrost effect. [6][7][8][9] The general principle is to trigger the rapid phase change of the liquid or of the solid to the vapour phase to create a lubrication film of vapour between the liquid or the solid and the substrate. In other words, the rapid generation of a light phase film due to a phase transition provoked by the proximity to an energy source isolates the material that changes of phase from the rest of the experiment.…”