Fingering patterns during droplet impact on heated surfaces.
Fingering patterns during droplet impact on heated surfaces.
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DOI：
10.1039/c4sm02878c
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发表时间：
2015-04
期刊：
影响因子：
3.4
通讯作者：
Mohammad Khavari;Chao Sun;D. Lohse;T. Tran
中科院分区：
文献类型：
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作者：
Mohammad Khavari;Chao Sun;D. Lohse;T. Tran
液滴撞击在充分加热的表面上可能会被其自身的蒸汽吸收而永远不会接触表面。在以前的工作中，过渡到这个所谓的莱顿弗罗斯特政权只是定性地描述为一个突然的变化之间的“接触沸腾”政权，其特征是暴力沸腾行为，和莱顿弗罗斯特状态。我们发现，润湿面积可以作为一个数量，定量表征这种转变，它是一个连续的函数的表面温度的莱顿弗罗斯特制度。润湿区域呈现出由液体下方的蒸气流动引起的指状图案。这强调了在莱顿弗罗斯特过渡的蒸气输送的关键作用，并揭示了过渡到莱顿弗罗斯特制度的物理机制。
A droplet impinging on a sufficiently heated surface may be cushioned by its own vapor and never touch the surface. In previous work, the transition to this so-called Leidenfrost regime was only qualitatively described as an abrupt change between the "contact-boiling" regime, which is characterized by violent boiling behaviors, and the Leidenfrost state. We reveal that the wetted area can be used as a quantity that quantitatively characterizes this transition and it is a continuous function of surface temperature up to the Leidenfrost regime. The wetted area exhibits fingering patterns caused by vapor flow under the liquid. This underlines the crucial role of vapor transport in the Leidenfrost transition and unveils the physical mechanism of the transition to the Leidenfrost regime.