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Numerical experiments on evaporation and explosive boiling of ultra-thin liquid argon film on aluminum nanostructure substrate.

Wang W, Zhang H, Tian C, Meng X - Nanoscale Res Lett (2015)

Bottom Line: Those simulations begin with an initial configuration for the complex liquid-vapor-solid system, followed by an equilibrating system at 90 K, and conclude with two different jump temperatures, including 150 and 310 K which are far beyond the critical temperature.The space and time dependences of temperature, pressure, density number, and net evaporation rate are monitored to investigate the phase transition process on a flat surface with and without nanostructures.The simulation results reveal that the nanostructures are of great help to raise the heat transfer efficiency and that evaporation rate increases with the nanostructures' height in a certain range.

View Article: PubMed Central - PubMed

Affiliation: Department of Electrical and Mechanical Engineering, Xidian University, No. 2 South Taibai Road, Xi'an, Shaanxi 710071 China ; State Key Laboratory for Manufacturing Systems Engineering, Xi'an Jiaotong University, No. 99 Yanxiang Road, Xi'an, Shaanxi 710054 China ; Department of Mechanical and Biomedical Engineering, City University of Hong Kong, Tat Chee Avenue, Kowloon, Hong Kong, China.

ABSTRACT
Evaporation and explosive boiling of ultra-thin liquid film are of great significant fundamental importance for both science and engineering applications. The evaporation and explosive boiling of ultra-thin liquid film absorbed on an aluminum nanostructure solid wall are investigated by means of molecular dynamics simulations. The simulated system consists of three regions: liquid argon, vapor argon, and an aluminum substrate decorated with nanostructures of different heights. Those simulations begin with an initial configuration for the complex liquid-vapor-solid system, followed by an equilibrating system at 90 K, and conclude with two different jump temperatures, including 150 and 310 K which are far beyond the critical temperature. The space and time dependences of temperature, pressure, density number, and net evaporation rate are monitored to investigate the phase transition process on a flat surface with and without nanostructures. The simulation results reveal that the nanostructures are of great help to raise the heat transfer efficiency and that evaporation rate increases with the nanostructures' height in a certain range.

No MeSH data available.


Related in: MedlinePlus

Snapshots of liquid argon evaporation process for the case with a 150 K heated source. (a) Surface 1, (b) surface 2, and (c) surface 3.
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Fig11: Snapshots of liquid argon evaporation process for the case with a 150 K heated source. (a) Surface 1, (b) surface 2, and (c) surface 3.

Mentions: In order to give a molecular insight into the phase transition for low temperature case, the simulation system for the three surfaces with nanostructures at different times is shown in Figure 11. Due to the low superheated temperature, surface 0 has no obvious evaporation phenomenon in the simulation time and is not shown in Figure 11, so it is clear that the surface with no nanostructures has low evaporate rate, which indicates that nanostructures play an important role in improving phase transition rate. In this case, liquid molecules escape into the vapor region from the top layer as individual atoms or as very tiny cluster, and another important phenomenon is that the nanostructures can also cause enhancement in the interaction between solid and liquid which results in a faster energy transfer from the solid substrate to the liquid film. As a result, the liquid film has a quicker response and then the thickness of the liquid film begins to decrease. The phenomenon similar to the high temperature is that for surface 2 and surface 3, the time taken in reaching equilibrium is almost same.Figure 11


Numerical experiments on evaporation and explosive boiling of ultra-thin liquid argon film on aluminum nanostructure substrate.

Wang W, Zhang H, Tian C, Meng X - Nanoscale Res Lett (2015)

Snapshots of liquid argon evaporation process for the case with a 150 K heated source. (a) Surface 1, (b) surface 2, and (c) surface 3.
© Copyright Policy - open-access
Related In: Results  -  Collection

License
Show All Figures
getmorefigures.php?uid=PMC4401484&req=5

Fig11: Snapshots of liquid argon evaporation process for the case with a 150 K heated source. (a) Surface 1, (b) surface 2, and (c) surface 3.
Mentions: In order to give a molecular insight into the phase transition for low temperature case, the simulation system for the three surfaces with nanostructures at different times is shown in Figure 11. Due to the low superheated temperature, surface 0 has no obvious evaporation phenomenon in the simulation time and is not shown in Figure 11, so it is clear that the surface with no nanostructures has low evaporate rate, which indicates that nanostructures play an important role in improving phase transition rate. In this case, liquid molecules escape into the vapor region from the top layer as individual atoms or as very tiny cluster, and another important phenomenon is that the nanostructures can also cause enhancement in the interaction between solid and liquid which results in a faster energy transfer from the solid substrate to the liquid film. As a result, the liquid film has a quicker response and then the thickness of the liquid film begins to decrease. The phenomenon similar to the high temperature is that for surface 2 and surface 3, the time taken in reaching equilibrium is almost same.Figure 11

Bottom Line: Those simulations begin with an initial configuration for the complex liquid-vapor-solid system, followed by an equilibrating system at 90 K, and conclude with two different jump temperatures, including 150 and 310 K which are far beyond the critical temperature.The space and time dependences of temperature, pressure, density number, and net evaporation rate are monitored to investigate the phase transition process on a flat surface with and without nanostructures.The simulation results reveal that the nanostructures are of great help to raise the heat transfer efficiency and that evaporation rate increases with the nanostructures' height in a certain range.

View Article: PubMed Central - PubMed

Affiliation: Department of Electrical and Mechanical Engineering, Xidian University, No. 2 South Taibai Road, Xi'an, Shaanxi 710071 China ; State Key Laboratory for Manufacturing Systems Engineering, Xi'an Jiaotong University, No. 99 Yanxiang Road, Xi'an, Shaanxi 710054 China ; Department of Mechanical and Biomedical Engineering, City University of Hong Kong, Tat Chee Avenue, Kowloon, Hong Kong, China.

ABSTRACT
Evaporation and explosive boiling of ultra-thin liquid film are of great significant fundamental importance for both science and engineering applications. The evaporation and explosive boiling of ultra-thin liquid film absorbed on an aluminum nanostructure solid wall are investigated by means of molecular dynamics simulations. The simulated system consists of three regions: liquid argon, vapor argon, and an aluminum substrate decorated with nanostructures of different heights. Those simulations begin with an initial configuration for the complex liquid-vapor-solid system, followed by an equilibrating system at 90 K, and conclude with two different jump temperatures, including 150 and 310 K which are far beyond the critical temperature. The space and time dependences of temperature, pressure, density number, and net evaporation rate are monitored to investigate the phase transition process on a flat surface with and without nanostructures. The simulation results reveal that the nanostructures are of great help to raise the heat transfer efficiency and that evaporation rate increases with the nanostructures' height in a certain range.

No MeSH data available.


Related in: MedlinePlus