Abstract
The Levitation of a droplet on a hot surface due to the rapid vaporization of the liquid at the proximity of the heat source is known as the Leidenfrost effect. This effect has been demonstrated when the surface is a solid or a liquid. Here, we explore the interaction between a liquid droplet and a hot granular material. The granular material is, by essence, a solid but adopts some behaviors similar to fluids. Surprisingly, we found that the droplet deeply penetrated the hot granular material. During the penetration process, the vapor production is so intense that the grains underneath the droplet are ejected. Consequently, the droplet moved downward under the action of gravity. A mechanism based on the Leidenfrost effect is proposed considering that the granular material can be modeled as a rough surface that can be eroded when the vapor speed is sufficient.
- Received 17 August 2021
- Accepted 22 February 2022
DOI:https://doi.org/10.1103/PhysRevFluids.7.034301
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