Lattice Boltzmann modeling of self-propelled Leidenfrost droplets on ratchet surfaces
- Central South Univ., Changsha (China). School of Energy Science and Engineering; Los Alamos National Lab. (LANL), Los Alamos, NM (United States). Computational Earth Science Group
- Los Alamos National Lab. (LANL), Los Alamos, NM (United States). Computational Earth Science Group
- Los Alamos National Lab. (LANL), Los Alamos, NM (United States). Fluid Dynamics and Solid Mechanics
- Southwest Univ. of Science and Technology, Mianyang (China). School of Civil Engineering and Architecture
Here in this paper, the self-propelled motion of Leidenfrost droplets on ratchet surfaces is numerically investigated with a thermal multiphase lattice Boltzmann model with liquid-vapor phase change. The capability of the model for simulating evaporation is validated via the D2 law. Using the model, we first study the performances of Leidenfrost droplets on horizontal ratchet surfaces. It is numerically shown that the motion of self-propelled Leidenfrost droplets on ratchet surfaces is owing to the asymmetry of the ratchets and the vapor flows beneath the droplets. It is found that the Leidenfrost droplets move in the direction toward the slowly inclined side from the ratchet peaks, which agrees with the direction of droplet motion in experiments [Linke et al., Phys. Rev. Lett., 2006, 96, 154502]. Moreover, the influences of the ratchet aspect ratio are investigated. For the considered ratchet surfaces, a critical value of the ratchet aspect ratio is approximately found, which corresponds to the maximum droplet moving velocity. Furthermore, the processes that the Leidenfrost droplets climb uphill on inclined ratchet surfaces are also studied. Lastly, numerical results show that the maximum inclination angle at which a Leidenfrost droplet can still climb uphill successfully is affected by the initial radius of the droplet.
- Research Organization:
- Los Alamos National Lab. (LANL), Los Alamos, NM (United States)
- Sponsoring Organization:
- USDOE Laboratory Directed Research and Development (LDRD) Program; National Natural Science Foundation of China (NSFC); Foundation for the Author of National Excellent Doctoral Dissertation of China
- Grant/Contract Number:
- AC52-06NA25396; 51506227; 201439
- OSTI ID:
- 1329863
- Report Number(s):
- LA-UR-15-24100
- Journal Information:
- Soft Matter, Vol. 12, Issue 1; ISSN 1744-683X
- Publisher:
- Royal Society of ChemistryCopyright Statement
- Country of Publication:
- United States
- Language:
- English
Web of Science
Similar Records
Asymmetric Wettability Directs Leidenfrost Droplets
Length scale selects directionality of droplets on vibrating pillar ratchet