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Figueroa ES, Trejo-Soto C, García-Ñustes M. A model for micro-front dynamics using a ϕ4 equation. CHAOS (WOODBURY, N.Y.) 2024; 34:023138. [PMID: 38412534 DOI: 10.1063/5.0187586] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/14/2023] [Accepted: 01/27/2024] [Indexed: 02/29/2024]
Abstract
In this article, we propose a numerical model based on the ϕ4 equation to simulate the dynamics of a front inside a microchannel that features an imperfection at a sidewall to different flow rates. The micro-front displays pinning-depinning phenomena without damped oscillations in the aftermath. To model this behavior, we propose a ϕ4 model with a localized external force and a damping coefficient. Numerical simulations with a constant damping coefficient show that the front displays pinning-depinning phenomena showing damped oscillations once the imperfection is overcome. Replacing the constant damping coefficient with a parabolic spatial function, we reproduce accurately the experimental front-defect interaction.
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Affiliation(s)
- Elram S Figueroa
- Instituto de Física, Pontificia Universidad Católica de Valparaíso, Casilla 4059, Chile
| | - Claudia Trejo-Soto
- Instituto de Física, Pontificia Universidad Católica de Valparaíso, Casilla 4059, Chile
| | - Mónica García-Ñustes
- Instituto de Física, Pontificia Universidad Católica de Valparaíso, Casilla 4059, Chile
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2
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Zheng SF, Wu ZY, Gao YY, Yang YR, Wang XD, Gross U. Asymmetric Condensation Characteristics during Dropwise Condensation in the Presence of Non-condensable Gas: A Lattice Boltzmann Study. LANGMUIR : THE ACS JOURNAL OF SURFACES AND COLLOIDS 2022; 38:9760-9776. [PMID: 35917451 DOI: 10.1021/acs.langmuir.2c00496] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/15/2023]
Abstract
In this work, the condensation characteristics of droplets considering the non-condensable gas with different interaction effects are numerically studied utilizing a multicomponent multiphase thermal lattice Boltzmann (LB) model, with a special focus on the asymmetric nature induced by the interaction effect. The results demonstrate that for isolated-like growth with negligible interactions, the condensation characteristics, that is, the concentration profile, the temperature distribution, and the flow pattern, are typically symmetric in nature. For the growth regime in a pattern, the droplet has to compete with its neighbors for catching vapor, which leads to an overlapping concentration profile (namely the interaction effect). The distribution of the condensation flux on the droplet surface is consequently modified, which contributes to the asymmetric flow pattern and temperature profile. The condensation characteristics for droplet growth in a pattern present an asymmetric nature. Significantly, the asymmetric condensation flux resulting from the interaction effect can induce droplet motion. The results further demonstrate that the interaction strongly depends on the droplet's spatial and size distribution, including two crucial parameters, namely the inter-distance and relative size of droplets. The asymmetric condensation characteristics are consequently dependent on the difference in the interaction intensities on both sides of the droplet. Finally, we demonstrate numerically and theoretically that the evolution of the droplet radius versus time can be suitably described by a power law; the corresponding exponent is kept at a constant of 0.50 for isolated-like growth and is strongly sensitive to the interaction effect for the growth in a pattern.
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Affiliation(s)
- Shao-Fei Zheng
- State Key Laboratory of Alternate Electrical Power System with Renewable Energy Sources, North China Electric Power University, Beijing 102206, China
- Research Center of Engineering Thermophysics, North China Electric Power University, Beijing 102206, China
| | - Zi-Yi Wu
- State Key Laboratory of Alternate Electrical Power System with Renewable Energy Sources, North China Electric Power University, Beijing 102206, China
- Research Center of Engineering Thermophysics, North China Electric Power University, Beijing 102206, China
| | - Yi-Ying Gao
- State Key Laboratory of Alternate Electrical Power System with Renewable Energy Sources, North China Electric Power University, Beijing 102206, China
- Research Center of Engineering Thermophysics, North China Electric Power University, Beijing 102206, China
| | - Yan-Ru Yang
- State Key Laboratory of Alternate Electrical Power System with Renewable Energy Sources, North China Electric Power University, Beijing 102206, China
- Research Center of Engineering Thermophysics, North China Electric Power University, Beijing 102206, China
| | - Xiao-Dong Wang
- State Key Laboratory of Alternate Electrical Power System with Renewable Energy Sources, North China Electric Power University, Beijing 102206, China
- Research Center of Engineering Thermophysics, North China Electric Power University, Beijing 102206, China
| | - Ulrich Gross
- Institute of Thermal Engineering, TU Bergakademie Freiberg, Gustav-Zeuner-Str. 7, 09599 Freiberg, Germany
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Fei L, Qin F, Wang G, Luo KH, Derome D, Carmeliet J. Droplet evaporation in finite-size systems: Theoretical analysis and mesoscopic modeling. Phys Rev E 2022; 105:025101. [PMID: 35291136 DOI: 10.1103/physreve.105.025101] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/18/2021] [Accepted: 01/17/2022] [Indexed: 06/14/2023]
Abstract
The classical D^{2}-Law states that the square of the droplet diameter decreases linearly with time during its evaporation process, i.e., D^{2}(t)=D_{0}^{2}-Kt, where D_{0} is the droplet initial diameter and K is the evaporation constant. Though the law has been widely verified by experiments, considerable deviations are observed in many cases. In this work, a revised theoretical analysis of the single droplet evaporation in finite-size open systems is presented for both two-dimensional (2D) and 3D cases. Our analysis shows that the classical D^{2}-Law is only applicable for 3D large systems (L≫D_{0}, L is the system size), while significant deviations occur for small (L≤5D_{0}) and/or 2D systems. Theoretical solution for the temperature field is also derived. Moreover, we discuss in detail the proper numerical implementation of droplet evaporation in finite-size open systems by the mesoscopic lattice Boltzmann method (LBM). Taking into consideration shrinkage effects and an adaptive pressure boundary condition, droplet evaporation in finite-size 2D/3D systems with density ratio up to 328 within a wide parameter range (K=[0.003,0.18] in lattice units) is simulated, and remarkable agreement with the theoretical solution is achieved, in contrast to previous simulations. The present work provides insights into realistic droplet evaporation phenomena and their numerical modeling using diffuse-interface methods.
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Affiliation(s)
- Linlin Fei
- Chair of Building Physics, Department of Mechanical and Process Engineering, ETH Zürich (Swiss Federal Institute of Technology in Zürich), Zürich 8092, Switzerland
| | - Feifei Qin
- Chair of Building Physics, Department of Mechanical and Process Engineering, ETH Zürich (Swiss Federal Institute of Technology in Zürich), Zürich 8092, Switzerland
| | - Geng Wang
- Department of Mechanical Engineering, University College London, Torrington Place, London WC1E 7JE, United Kingdom
| | - Kai H Luo
- Department of Mechanical Engineering, University College London, Torrington Place, London WC1E 7JE, United Kingdom
| | - Dominique Derome
- Department of Civil and Building Engineering, Université de Sherbrooke, Sherbrooke, QC J1K 2R1, Canada
| | - Jan Carmeliet
- Chair of Building Physics, Department of Mechanical and Process Engineering, ETH Zürich (Swiss Federal Institute of Technology in Zürich), Zürich 8092, Switzerland
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Chandra NK, Ghosh UU, Saha A, Kumar A. Contact Line Pinning and Depinning Can Modulate the Rod-Climbing Effect. LANGMUIR : THE ACS JOURNAL OF SURFACES AND COLLOIDS 2021; 37:14785-14792. [PMID: 34813341 DOI: 10.1021/acs.langmuir.1c01861] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/13/2023]
Abstract
Our experiments on the rod-climbing effect with an oil-coated rod revealed two key differences in the rod-climbing phenomena compared to a bare rod. First, an enhancement in the magnitude of climbing height for any particular value of the rod rotational speed and second, a decrease in the threshold rod rotational speed required for the appearance of the rod-climbing effect were observed. Observed phenomena are explained by considering the contact line behavior at the rod-fluid interface. Transient evolution of the meniscus at the rod-fluid interface revealed that the three-phase contact line was pinned for a bare rod and depinned for an oil-coated rod. We modeled the subject fluid as a Giesekus fluid to predict the climbing height. The differences in the contact line behavior were incorporated via the contact angle at the rod-fluid interface as a boundary condition. Agreement was found between the observed and predicted climbing height, establishing that contact line behavior may modulate the rod-climbing effect.
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Affiliation(s)
- Navin Kumar Chandra
- Department of Mechanical Engineering, Indian Institute of Science, Bangalore 560012, India
| | - Udita U Ghosh
- Department of Chemical Engineering and Technology, Indian Institute of Technology (BHU), Varanasi 221005, India
| | - Aniruddha Saha
- Department of Mechanical Engineering, Indian Institute of Technology, Kharagpur 721302, India
| | - Aloke Kumar
- Department of Mechanical Engineering, Indian Institute of Science, Bangalore 560012, India
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Numerical coffee-ring patterns with new interfacial schemes in 3D hybrid LB-LE model. POWDER TECHNOL 2021. [DOI: 10.1016/j.powtec.2021.07.012] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
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Davoodabadi A, Ghasemi H. Evaporation in nano/molecular materials. Adv Colloid Interface Sci 2021; 290:102385. [PMID: 33662599 DOI: 10.1016/j.cis.2021.102385] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/15/2020] [Revised: 02/17/2021] [Accepted: 02/18/2021] [Indexed: 12/29/2022]
Abstract
Evaporation is a physical phenomenon with fundamental significance to both nature and technology ranging from plant transpiration to DNA engineering. Various analytical and empirical relationships have been proposed to characterize evaporation kinetics at macroscopic scales. However, theoretical models to describe the kinetics of evaporation from nano and sub-nanometer (molecular) confinements are absent. On the other hand, the fast advancements in technology concentrated on development of nano/molecular-scale devices demand appropriate models that can accurately predict physics of phase-change in these systems. A thorough understanding of the physics of evaporation in nano/molecular materials is, thus, of critical importance to develop the required models. This understanding is also crucial to explain the intriguing evaporation-related phenomena that only take place when the characteristic length of the system drops to several nanometers. Here, we comprehensively review the underlying physics of evaporation phenomenon and discuss the effects of nano/molecular confinement on evaporation. The role of liquid-wall interface-related phenomena including the effects of disjoining pressure and flow slippage on evaporation from nano/molecular confinements are discussed. Different driving forces that can induce evaporation in small confinements, such as heat transfer, pressure drop, cavitation and density fluctuations are elaborated. Hydrophobic confinement induced evaporation and its potential application for synthetic ion channels are discussed in detail. Evaporation of water as molecular clusters rather than isolated molecules is discussed. Despite the lack of experimental investigations on evaporation at nanoscale, there exist an extensive body of literature that have applied different simulation techniques to predict the phase change behavior of liquids in nanoconfinements. We infer that exploring the effect of electrostatic interactions and flow slippage to enhance evaporation from nanoconduits is an interesting topic for future endeavors. Further future studies could be devoted to developing nano/molecular channels with evaporation-based gating mechanism and utilization of 2D materials to tune energy barrier for evaporation leading to enhanced evaporation.
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Dou S, Hao L. Numerical study of droplet evaporation on heated flat and micro-pillared hydrophobic surfaces by using the lattice Boltzmann method. Chem Eng Sci 2021. [DOI: 10.1016/j.ces.2020.116032] [Citation(s) in RCA: 7] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/23/2022]
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Zhou H, Huang Z, Cai Z, Zhang R, Wang H, Song Y, Reichmanis E. Patterning Bubbles by the Stick-Slip Motion of the Advancing Triple Phase Line on Nanostructures. LANGMUIR : THE ACS JOURNAL OF SURFACES AND COLLOIDS 2018; 34:15804-15811. [PMID: 30452276 DOI: 10.1021/acs.langmuir.8b03135] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/09/2023]
Abstract
The stick-slip motion of the triple phase contact line (TCL) has wide applications in inkjet printing, surface coatings, functional material assembly, and device fabrication. Here, for the first time, we report that on an alumina substrate with nanostructures, the stick-slip motion of the advancing TCL during spreading of an emulsion droplet can serve as an effective nanopatterning process. Air enclosed in the substrate nanostructures can be exchanged with liquid during the "stick" phase, resulting in the formation of bubbles arranged in a ring pattern. The process takes place in two stages: rings of air form first and then, as the volume of air increases, they separate into air bubbles as a result of the Plateau Rayleigh instability. During the first stage, the rings form due to the stick-slip of the advancing TCL and are ascribed to hydrogen-bonding interactions. Ultimate bubble size is dependent on the substrate pore dimensions. The process was simulated using finite-element analysis to elucidate the mechanism associated with subsequent bubble formation. The simulations corroborate well with the experimental results. This stick-slip motion of the advancing TCL provides new insights into the phenomena associated with droplet spreading and wetting, and the ability to control the formation of patterned bubbles will be promising in applications ranging from microfluidics to printing of functional materials and devices based on bubble templates and applications requiring submerged hydrophobic surface.
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Affiliation(s)
- Haihua Zhou
- Key Laboratory of Green Printing, Institute of Chemistry , Chinese Academy of Sciences , Beijing 100190 , China
- Beijing National Laboratory for Molecular Science (BNLMS) , Beijing 100190 , China
| | - Zhandong Huang
- Key Laboratory of Green Printing, Institute of Chemistry , Chinese Academy of Sciences , Beijing 100190 , China
- Beijing National Laboratory for Molecular Science (BNLMS) , Beijing 100190 , China
| | - Zheren Cai
- Key Laboratory of Green Printing, Institute of Chemistry , Chinese Academy of Sciences , Beijing 100190 , China
- Beijing National Laboratory for Molecular Science (BNLMS) , Beijing 100190 , China
| | - Rui Zhang
- Key Laboratory of Green Printing, Institute of Chemistry , Chinese Academy of Sciences , Beijing 100190 , China
- Beijing National Laboratory for Molecular Science (BNLMS) , Beijing 100190 , China
| | - Haiyan Wang
- Key Laboratory of Green Printing, Institute of Chemistry , Chinese Academy of Sciences , Beijing 100190 , China
- Beijing National Laboratory for Molecular Science (BNLMS) , Beijing 100190 , China
| | - Yanlin Song
- Key Laboratory of Green Printing, Institute of Chemistry , Chinese Academy of Sciences , Beijing 100190 , China
- Beijing National Laboratory for Molecular Science (BNLMS) , Beijing 100190 , China
| | - Elsa Reichmanis
- School of Chemical and Biomolecular Engineering , Georgia Institute of Technology , Atlanta , Georgia 30332-0100 , United States
- School of Chemistry and Biochemistry , Georgia Institute of Technology , Atlanta , Georgia 30332-0400 , United States
- School of Materials Science and Engineering , Georgia Institute of Technology , Atlanta , Georgia 30332-0245 , United States
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Jafari P, Masoudi A, Irajizad P, Nazari M, Kashyap V, Eslami B, Ghasemi H. Evaporation Mass Flux: A Predictive Model and Experiments. LANGMUIR : THE ACS JOURNAL OF SURFACES AND COLLOIDS 2018; 34:11676-11684. [PMID: 30188721 DOI: 10.1021/acs.langmuir.8b02289] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/08/2023]
Abstract
Evaporation is a fundamental and core phenomenon in a broad range of disciplines including power generation and refrigeration systems, desalination, electronic/photonic cooling, aviation systems, and even biosciences. Despite its importance, the current theories on evaporation suffer from fitting coefficients with reported values varying in a few orders of magnitude. Lack of a sound model impedes simulation and prediction of characteristics of many systems in these disciplines. Here, we studied evaporation at a planar liquid-vapor interface through a custom-designed, controlled, and automated experimental setup. This experimental setup provides the ability to accurately probe thermodynamic properties in vapor, liquid, and close to the liquid-vapor interface. Through analysis of these thermodynamic properties in a wide range of evaporation mass fluxes, we cast a predictive model of evaporation based on nonequilibrium thermodynamics with no fitting parameters. In this model, only the interfacial temperatures of liquid and vapor phases along with the vapor pressure are needed to predict evaporation mass flux. The model was validated by the reported study of an independent research group. The developed model provides a foundation for all liquid-vapor phase change studies including energy, water, and biological systems.
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Affiliation(s)
- Parham Jafari
- Department of Mechanical Engineering , University of Houston , 4726 Calhoun Rd , Houston , Texas 77204-4006 , United States
| | - Ali Masoudi
- Department of Mechanical Engineering , University of Houston , 4726 Calhoun Rd , Houston , Texas 77204-4006 , United States
| | - Peyman Irajizad
- Department of Mechanical Engineering , University of Houston , 4726 Calhoun Rd , Houston , Texas 77204-4006 , United States
| | - Masoumeh Nazari
- Department of Mechanical Engineering , University of Houston , 4726 Calhoun Rd , Houston , Texas 77204-4006 , United States
| | - Varun Kashyap
- Department of Mechanical Engineering , University of Houston , 4726 Calhoun Rd , Houston , Texas 77204-4006 , United States
| | - Bahareh Eslami
- Department of Mechanical Engineering , University of Houston , 4726 Calhoun Rd , Houston , Texas 77204-4006 , United States
| | - Hadi Ghasemi
- Department of Mechanical Engineering , University of Houston , 4726 Calhoun Rd , Houston , Texas 77204-4006 , United States
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