TY - JOUR
T1 - On explosive boiling of a multicomponent Leidenfrost drop
AU - Lyua, Sijia
AU - Tan, Huanshu
AU - Wakata, Yuki
AU - Yang, Xianjun
AU - Law, Chung K.
AU - Lohse, Detlef
AU - Sun, Chao
N1 - Funding Information:
ACKNOWLEDGMENTS. We thank X. Chao, Y. C. Liu, and Y. S. Li for insightful discussions. The work was supported by Natural Science Foundation of China Grant 11988102, National Natural Science Foundation of China Joint Research Program 11861131005, Deutsche Forschungsgemeinschaft Program OH 75/3-1, and Tsinghua University Initiative Scientific Research Program 20193080058.
Publisher Copyright:
© 2021 National Academy of Sciences. All rights reserved.
PY - 2021/1/12
Y1 - 2021/1/12
N2 - The gasification of multicomponent fuel drops is relevant in various energy-related technologies. An interesting phenomenon associated with this process is the self-induced explosion of the drop, producing a multitude of smaller secondary droplets, which promotes overall fuel atomization and, consequently, improves the combustion efficiency and reduces emissions of liquid-fueled engines. Here, we study a unique explosive gasification process of a tricomponent droplet consisting of water, ethanol, and oil ("ouzo"), by high-speed monitoring of the entire gasification event taking place in the well-controlled, levitated Leidenfrost state over a superheated plate. It is observed that the preferential evaporation of the most volatile component, ethanol, triggers nucleation of the oil microdroplets/nanodroplets in the remaining drop, which, consequently, becomes an opaque oil-in-water microemulsion. The tiny oil droplets subsequently coalesce into a large one, which, in turn, wraps around the remnant water. Because of the encapsulating oil layer, the droplet can no longer produce enough vapor for its levitation, and, thus, falls and contacts the superheated surface. The direct thermal contact leads to vapor bubble formation inside the drop and consequently drop explosion in the final stage.
AB - The gasification of multicomponent fuel drops is relevant in various energy-related technologies. An interesting phenomenon associated with this process is the self-induced explosion of the drop, producing a multitude of smaller secondary droplets, which promotes overall fuel atomization and, consequently, improves the combustion efficiency and reduces emissions of liquid-fueled engines. Here, we study a unique explosive gasification process of a tricomponent droplet consisting of water, ethanol, and oil ("ouzo"), by high-speed monitoring of the entire gasification event taking place in the well-controlled, levitated Leidenfrost state over a superheated plate. It is observed that the preferential evaporation of the most volatile component, ethanol, triggers nucleation of the oil microdroplets/nanodroplets in the remaining drop, which, consequently, becomes an opaque oil-in-water microemulsion. The tiny oil droplets subsequently coalesce into a large one, which, in turn, wraps around the remnant water. Because of the encapsulating oil layer, the droplet can no longer produce enough vapor for its levitation, and, thus, falls and contacts the superheated surface. The direct thermal contact leads to vapor bubble formation inside the drop and consequently drop explosion in the final stage.
KW - Internal interaction
KW - Leidenfrost state
KW - Multicomponent drop
KW - Mutual solubility differential
KW - Volatility differentials
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U2 - 10.1073/PNAS.2016107118
DO - 10.1073/PNAS.2016107118
M3 - Article
C2 - 33419924
AN - SCOPUS:85099721993
VL - 118
JO - Proceedings of the National Academy of Sciences of the United States of America
JF - Proceedings of the National Academy of Sciences of the United States of America
SN - 0027-8424
IS - 2
M1 - 2016107118
ER -