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Insights from molecular simulations on liquid slip over nanostructured surfaces. J Mol Model 2022; 28:346. [PMID: 36205823 DOI: 10.1007/s00894-022-05338-x] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/26/2022] [Accepted: 09/28/2022] [Indexed: 10/10/2022]
Abstract
The current study focuses on non-equilibrium molecular dynamics (NEMD) simulations to investigate the slip properties of water flowing over different nanostructured surfaces. A simulation protocol is developed that applies constant shear stress throughout the fluid before measuring the slip length. Using pseudo-data, the reliability of this protocol in terms of both accuracy and noise of the results for high-slip and multiphase systems is demonstrated. In contrast to the NEMD techniques available in the literature, the protocol also enables a convenient way to compare the slip lengths of different surface coatings. The fluid slip lengths of surface coatings comprising carbon nanotubes on platinum are predicted using the proposed protocol with nitrogen gas trapped in the interstitial gaps. The role of these gas pockets in determining surface slip properties is investigated. The NEMD results from the proposed model compare well with a macroscopic theoretical model for nano-patterned surfaces. Finally, it is concluded that entrapped gas within nanostructures may offer significant drag reduction only if the gas surface coverage is above 95%.
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Wang R, Chai J, Luo B, Liu X, Zhang J, Wu M, Wei M, Ma Z. A review on slip boundary conditions at the nanoscale: recent development and applications. BEILSTEIN JOURNAL OF NANOTECHNOLOGY 2021; 12:1237-1251. [PMID: 34868800 PMCID: PMC8609245 DOI: 10.3762/bjnano.12.91] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 07/21/2021] [Accepted: 11/01/2021] [Indexed: 06/13/2023]
Abstract
The slip boundary condition for nanoflows is a key component of nanohydrodynamics theory, and can play a significant role in the design and fabrication of nanofluidic devices. In this review, focused on the slip boundary conditions for nanoconfined liquid flows, we firstly summarize some basic concepts about slip length including its definition and categories. Then, the effects of different interfacial properties on slip length are analyzed. On strong hydrophilic surfaces, a negative slip length exists and varies with the external driving force. In addition, depending on whether there is a true slip length, the amplitude of surface roughness has different influences on the effective slip length. The composition of surface textures, including isotropic and anisotropic textures, can also affect the effective slip length. Finally, potential applications of nanofluidics with a tunable slip length are discussed and future directions related to slip boundary conditions for nanoscale flow systems are addressed.
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Affiliation(s)
- Ruifei Wang
- Shaanxi Key Laboratory of Well Stability and Fluid & Rock Mechanics in Oil and Gas Reservoirs, College of Petroleum Engineering, Xi’an Shiyou University, 710065, China
| | - Jin Chai
- Shaanxi Key Laboratory of Well Stability and Fluid & Rock Mechanics in Oil and Gas Reservoirs, College of Petroleum Engineering, Xi’an Shiyou University, 710065, China
| | - Bobo Luo
- Research Institute of Exploration and Development, Zhongyuan Oilfield Company, SINOPEC, Puyang 457001, China
| | - Xiong Liu
- Shaanxi Key Laboratory of Well Stability and Fluid & Rock Mechanics in Oil and Gas Reservoirs, College of Petroleum Engineering, Xi’an Shiyou University, 710065, China
| | - Jianting Zhang
- Shaanxi Key Laboratory of Well Stability and Fluid & Rock Mechanics in Oil and Gas Reservoirs, College of Petroleum Engineering, Xi’an Shiyou University, 710065, China
| | - Min Wu
- Shaanxi Key Laboratory of Well Stability and Fluid & Rock Mechanics in Oil and Gas Reservoirs, College of Petroleum Engineering, Xi’an Shiyou University, 710065, China
| | - Mingdan Wei
- Shaanxi Key Laboratory of Well Stability and Fluid & Rock Mechanics in Oil and Gas Reservoirs, College of Petroleum Engineering, Xi’an Shiyou University, 710065, China
| | - Zhuanyue Ma
- Shaanxi Key Laboratory of Well Stability and Fluid & Rock Mechanics in Oil and Gas Reservoirs, College of Petroleum Engineering, Xi’an Shiyou University, 710065, China
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3
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Lin Z, Liu L, Liu C, Gao X. Adsorptive separation of Xe/Kr using nanoporous carbons in the presence of I2 and CH3I. Sep Purif Technol 2021. [DOI: 10.1016/j.seppur.2021.119161] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/25/2022]
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4
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Cheng L, Fan B, Zhang Z, Bandaru P. Influence of Surface Texture on the Variation of Electrokinetic Streaming Potentials. LANGMUIR : THE ACS JOURNAL OF SURFACES AND COLLOIDS 2021; 37:6736-6743. [PMID: 34019765 DOI: 10.1021/acs.langmuir.1c00738] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/12/2023]
Abstract
The electrokinetic streaming potential (Vs) obtained through electrolyte flow in a microchannel is shown to be related to the underlying surface pattern. Pillar, mesh, and groove patterns were studied for comparing the relative magnitudes of the Vs with air-/liquid-filled surfaces. A record value of the related figure of merit, in terms of the developed Vs per-unit applied pressure, of ∼0.127 mV/Pa, was observed in a mesh texture liquid-filled surface (LFS) impregnated with an electrolyte-immiscible oil. The study indicated that increasing the solid fraction of the pattern surface decreases the effective slip length while enhancing the overall channel ζ potential. Consequently, maximizing the obtained Vs implies a balancing of the slip with the surface potential, with plausibly more significance of the latter. The work has implications for higher-efficiency electrical voltage sources.
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Affiliation(s)
| | - Bei Fan
- Department of Mechanical Engineering, Michigan State University, East Lansing, Michigan 48824, United States
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Kharazmi A, Priezjev NV. Molecular Dynamics Simulations of the Rotational and Translational Diffusion of a Janus Rod-Shaped Nanoparticle. J Phys Chem B 2017; 121:7133-7139. [PMID: 28714312 DOI: 10.1021/acs.jpcb.7b03720] [Citation(s) in RCA: 17] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/01/2023]
Abstract
The diffusion of a Janus rod-shaped nanoparticle in a dense Lennard-Jones fluid is studied using molecular dynamics (MD) simulations. The Janus particle is modeled as a rigid cylinder whose atoms at each end have different interaction energies with fluid molecules, thus comprising wetting and nonwetting surfaces. We found that both rotational and translational diffusion coefficients are larger for Janus particles with lower average wettability, and these values are bound between the two limiting cases of uniformly wetting and nonwetting particles. It was also shown that values of the diffusion coefficients for displacements parallel and perpendicular to the major axis of a uniformly wetting particle agree well with analytical predictions despite a finite slip at the particle surface present in MD simulations. It was further demonstrated that diffusion of Janus particles is markedly different from that of uniform particles; namely, Janus particles preferentially rotate and orient their nonwetting ends along the displacement vector to reduce drag. This correlation between translation and rotation is consistent with the previous results on diffusive dynamics of a spherical Janus particle with two hemispheres of different wettability.
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Affiliation(s)
- Ali Kharazmi
- Department of Mechanical Engineering, Michigan State University , East Lansing, Michigan 48824, United States
| | - Nikolai V Priezjev
- Department of Mechanical and Materials Engineering, Wright State University , Dayton, Ohio 45435, United States.,National Research University Higher School of Economics , Moscow 101000, Russia
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Bhatia SK. Characterizing Structural Complexity in Disordered Carbons: From the Slit Pore to Atomistic Models. LANGMUIR : THE ACS JOURNAL OF SURFACES AND COLLOIDS 2017; 33:831-847. [PMID: 27996264 DOI: 10.1021/acs.langmuir.6b03459] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/06/2023]
Abstract
The reliable characterization of nanoporous carbons is critical to the design and optimization of their numerous applications; however, the vast majority of carbons in industrial use are highly disordered, with complex structures whose understanding has long challenged researchers. The idealized slit pore model represents the most commonly used approximation to a carbon nanopore; nevertheless, it has been only partially successful in predicting adsorption isotherms and fails significantly in predicting transport properties because of its inability to capture structural disorder and its effect on fluid accessibility. Atomistic modeling of the structure has much potential for overcoming this limitation, and among such approaches, hybrid reverse Monte Carlo simulation has emerged as the most attractive. This method reconstructs the structure of a carbon based on the fitting of its experimentally measured pair distribution function and appropriate properties such as porosity while minimizing the energy. The method is shown to be best implemented using a multistage strategy, with the first stage used to attain a deep minimum of the energy and subsequent stages to refine the structure based on the fitting of specific properties. Methods to determine the accessibility of gases based on the atomistic structure are outlined, and it is shown that energy barriers are very sensitive to small differences in the sizes of constrictions and pore entries. The ability to accurately predict macroscopic transport coefficients of adsorbates in nanoporous carbons appears to be the greatest limitation of such models. Overcoming this will require the fitting of properties more sensitive to long-range disorder than the currently used pair distribution and the use of a suitable multiscaling strategy, which is suggested as a future direction for advancing atomistic models. The inclusion of heteroatoms in the structure is also an important area requiring further attention, particularly in the development of computationally efficient force fields incorporating their interactions.
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Affiliation(s)
- Suresh K Bhatia
- School of Chemical Engineering, The University of Queensland , St. Lucia, QLD 4072, Australia
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7
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Sega M, Sbragaglia M, Biferale L, Succi S. The importance of chemical potential in the determination of water slip in nanochannels. THE EUROPEAN PHYSICAL JOURNAL. E, SOFT MATTER 2015; 38:127. [PMID: 26614498 DOI: 10.1140/epje/i2015-15127-y] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/20/2015] [Accepted: 10/30/2015] [Indexed: 06/05/2023]
Abstract
We investigate the slip properties of water confined in graphite-like nanochannels by non-equilibrium molecular dynamics simulations, with the aim of identifying and analyze separately the influence of different physical quantities on the slip length. In a system under confinement but connected to a reservoir of fluid, the chemical potential is the natural control parameter: we show that two nanochannels characterized by the same macroscopic contact angle--but a different microscopic surface potential--do not exhibit the same slip length unless the chemical potential of water in the two channels is matched. Some methodological issues related to the preparation of samples for the comparative analysis in confined geometries are also discussed.
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Affiliation(s)
- M Sega
- Institute of Computational Physics, University of Vienna, Sensengasse 8/9, 1090, Vienna, Austria.
| | - M Sbragaglia
- Department of Physics and INFN, University of "Tor Vergata", Via della Ricerca Scientifica 1, 00133, Rome, Italy
| | - L Biferale
- Department of Physics and INFN, University of "Tor Vergata", Via della Ricerca Scientifica 1, 00133, Rome, Italy
| | - S Succi
- Istituto per le Applicazioni del Calcolo CNR, Via dei Taurini 19, 00185, Rome, Italy
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8
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Kharazmi A, Priezjev NV. Diffusion of a Janus nanoparticle in an explicit solvent: A molecular dynamics simulation study. J Chem Phys 2015; 142:234503. [PMID: 26093564 DOI: 10.1063/1.4922689] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022] Open
Abstract
Molecular dynamics simulations are carried out to study the translational and rotational diffusion of a single Janus particle immersed in a dense Lennard-Jones fluid. We consider a spherical particle with two hemispheres of different wettabilities. The analysis of the particle dynamics is based on the time-dependent orientation tensor, particle displacement, as well as the translational and angular velocity autocorrelation functions. It was found that both translational and rotational diffusion coefficients increase with decreasing surface energy at the nonwetting hemisphere, provided that the wettability of the other hemisphere remains unchanged. We also observed that in contrast to homogeneous particles, the nonwetting hemisphere of the Janus particle tends to rotate in the direction of the displacement vector during the rotational relaxation time.
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Affiliation(s)
- Ali Kharazmi
- Department of Mechanical Engineering, Michigan State University, East Lansing, Michigan 48824, USA
| | - Nikolai V Priezjev
- Department of Mechanical and Materials Engineering, Wright State University, Dayton, Ohio 45435, USA
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Nizkaya TV, Asmolov ES, Zhou J, Schmid F, Vinogradova OI. Flows and mixing in channels with misaligned superhydrophobic walls. PHYSICAL REVIEW. E, STATISTICAL, NONLINEAR, AND SOFT MATTER PHYSICS 2015; 91:033020. [PMID: 25871215 DOI: 10.1103/physreve.91.033020] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/23/2014] [Indexed: 06/04/2023]
Abstract
Aligned superhydrophobic surfaces with the same texture orientation reduce drag in the channel and generate secondary flows transverse to the direction of the applied pressure gradient. Here we show that a transverse shear can be easily generated by using superhydrophobic channels with misaligned textured surfaces. We propose a general theoretical approach to quantify this transverse flow by introducing the concept of an effective shear tensor. To illustrate its use, we present approximate theoretical solutions and Dissipative Particle Dynamics simulations for striped superhydrophobic channels. Our results demonstrate that the transverse shear leads to complex flow patterns, which provide a new mechanism of a passive vertical mixing at the scale of a texture period. Depending on the value of Reynolds number two different scenarios occur. At relatively low Reynolds number the flow represents a transverse shear superimposed with two corotating vortices. For larger Reynolds number these vortices become isolated, by suppressing fluid transport in the transverse direction.
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Affiliation(s)
- Tatiana V Nizkaya
- A.N. Frumkin Institute of Physical Chemistry and Electrochemistry, Russian Academy of Science, 31 Leninsky Prospect, 119991 Moscow, Russia
| | - Evgeny S Asmolov
- A.N. Frumkin Institute of Physical Chemistry and Electrochemistry, Russian Academy of Science, 31 Leninsky Prospect, 119991 Moscow, Russia
- Central Aero-Hydrodynamic Institute, 140180 Zhukovsky, Moscow region, Russia
| | - Jiajia Zhou
- Institut für Physik, Johannes Gutenberg-Universität Mainz, D55099 Mainz, Germany
| | - Friederike Schmid
- Institut für Physik, Johannes Gutenberg-Universität Mainz, D55099 Mainz, Germany
| | - Olga I Vinogradova
- A.N. Frumkin Institute of Physical Chemistry and Electrochemistry, Russian Academy of Science, 31 Leninsky Prospect, 119991 Moscow, Russia
- Department of Physics, M.V. Lomonosov Moscow State University, 119991 Moscow, Russia
- DWI-Leibniz Institute for Interactive Materials, RWTH Aachen, Forckenbeckstrasse 50, 52056 Aachen, Germany
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Lee T, Charrault E, Neto C. Interfacial slip on rough, patterned and soft surfaces: a review of experiments and simulations. Adv Colloid Interface Sci 2014; 210:21-38. [PMID: 24630344 DOI: 10.1016/j.cis.2014.02.015] [Citation(s) in RCA: 102] [Impact Index Per Article: 10.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/02/2013] [Revised: 02/14/2014] [Accepted: 02/15/2014] [Indexed: 11/26/2022]
Abstract
Advancements in the fabrication of microfluidic and nanofluidic devices and the study of liquids in confined geometries rely on understanding the boundary conditions for the flow of liquids at solid surfaces. Over the past ten years, a large number of research groups have turned to investigating flow boundary conditions, and the occurrence of interfacial slip has become increasingly well-accepted and understood. While the dependence of slip on surface wettability is fairly well understood, the effect of other surface modifications that affect surface roughness, structure and compliance, on interfacial slip is still under intense investigation. In this paper we review investigations published in the past ten years on boundary conditions for flow on complex surfaces, by which we mean rough and structured surfaces, surfaces decorated with chemical patterns, grafted with polymer layers, with adsorbed nanobubbles, and superhydrophobic surfaces. The review is divided in two interconnected parts, the first dedicated to physical experiments and the second to computational experiments on interfacial slip of simple (Newtonian) liquids on these complex surfaces. Our work is intended as an entry-level review for researchers moving into the field of interfacial slip, and as an indication of outstanding problems that need to be addressed for the field to reach full maturity.
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11
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Zhang C, Chen Y, Peterson GP. Thermal slip for liquids at rough solid surfaces. PHYSICAL REVIEW. E, STATISTICAL, NONLINEAR, AND SOFT MATTER PHYSICS 2014; 89:062407. [PMID: 25019794 DOI: 10.1103/physreve.89.062407] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/13/2012] [Indexed: 06/03/2023]
Abstract
Molecular dynamics simulation is used to examine the thermal slip of liquids at rough solid surfaces as characterized by fractal Cantor structures. The temperature profiles, potential energy distributions, thermal slip, and interfacial thermal resistance are investigated and evaluated for a variety of surface topographies. In addition, the effects of liquid-solid interaction, surface stiffness, and boundary condition on thermal slip length are presented. Our results indicate that the presence of roughness expands the low potential energy regions in adjacent liquids, enhances the energy transfer at liquid-solid interface, and decreases the thermal slip. Interestingly, the thermal slip length and thermal resistance for liquids in contact with solid surfaces depends not only on the statistical roughness height, but also on the fractal dimension (i.e., topographical spectrum).
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Affiliation(s)
- Chengbin Zhang
- Key Laboratory of Energy Thermal Conversion and Control of Ministry of Education, School of Energy and Environment, Southeast University, Nanjing, Jiangsu 210096, PR China
| | - Yongping Chen
- Key Laboratory of Energy Thermal Conversion and Control of Ministry of Education, School of Energy and Environment, Southeast University, Nanjing, Jiangsu 210096, PR China
| | - G P Peterson
- George W. Woodruff School of Mechanical Engineering, Georgia Institute of Technology, Atlanta, Georgia 30332-0325, USA
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12
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Huang K, Szlufarska I. Green-Kubo relation for friction at liquid-solid interfaces. PHYSICAL REVIEW. E, STATISTICAL, NONLINEAR, AND SOFT MATTER PHYSICS 2014; 89:032119. [PMID: 24730802 DOI: 10.1103/physreve.89.032119] [Citation(s) in RCA: 21] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/19/2013] [Indexed: 06/03/2023]
Abstract
We have developed a Green-Kubo relation that enables accurate calculations of friction at solid-liquid interfaces directly from equilibrium molecular dynamics (MD) simulations and that provides a pathway to bypass the time-scale limitations of typical nonequilibrium MD simulations. The theory has been validated for a number of different interfaces and it is demonstrated that the liquid-solid slip is an intrinsic property of an interface. Because of the high numerical efficiency of our method, it can be used in the design of interfaces for applications in aqueous environments, such as nano- and microfluidics.
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Affiliation(s)
- Kai Huang
- Materials Science Program, University of Wisconsin, Madison, Wisconsin 53706-1595, USA
| | - Izabela Szlufarska
- Materials Science Program, University of Wisconsin, Madison, Wisconsin 53706-1595, USA and Department of Materials Science and Engineering, University of Wisconsin, Madison, Wisconsin 53706-1595, USA
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13
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Dubov AL, Schmieschek S, Asmolov ES, Harting J, Vinogradova OI. Lattice-Boltzmann simulations of the drag force on a sphere approaching a superhydrophobic striped plane. J Chem Phys 2014; 140:034707. [DOI: 10.1063/1.4861896] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022] Open
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14
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Zhou J, Asmolov ES, Schmid F, Vinogradova OI. Effective slippage on superhydrophobic trapezoidal grooves. J Chem Phys 2013; 139:174708. [DOI: 10.1063/1.4827867] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022] Open
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15
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Asmolov ES, Zhou J, Schmid F, Vinogradova OI. Effective slip-length tensor for a flow over weakly slipping stripes. PHYSICAL REVIEW. E, STATISTICAL, NONLINEAR, AND SOFT MATTER PHYSICS 2013; 88:023004. [PMID: 24032921 DOI: 10.1103/physreve.88.023004] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/09/2013] [Revised: 06/19/2013] [Indexed: 06/02/2023]
Abstract
We discuss the flow past a flat heterogeneous solid surface decorated by slipping stripes. The spatially varying slip length, b(y), is assumed to be small compared to the scale of the heterogeneities, L, but finite. For such weakly slipping surfaces, earlier analyses have predicted that the effective slip length is simply given by the surface-averaged slip length, which implies that the effective slip-length tensor becomes isotropic. Here we show that a different scenario is expected if the local slip length has steplike jumps at the edges of slipping heterogeneities. In this case, the next-to-leading term in an expansion of the effective slip-length tensor in powers of max[b(y)/L] becomes comparable to the leading-order term, but anisotropic, even at very small b(y)/L. This leads to an anisotropy of the effective slip and to its significant reduction compared to the surface-averaged value. The asymptotic formulas are tested by numerical solutions and are in agreement with results of dissipative particle dynamics simulations.
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Affiliation(s)
- Evgeny S Asmolov
- A.N. Frumkin Institute of Physical Chemistry and Electrochemistry, Russian Academy of Sciences, 31 Leninsky Prospect, 119071 Moscow, Russia and Central Aero-Hydrodynamic Institute, 140180 Zhukovsky, Moscow region, Russia and Institute of Mechanics, M. V. Lomonosov Moscow State University, 119071 Moscow, Russia
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Pham TT, To QD, Lauriat G, Léonard C. Tensorial slip theory for gas flows and comparison with molecular dynamics simulations using an anisotropic gas-wall collision mechanism. PHYSICAL REVIEW. E, STATISTICAL, NONLINEAR, AND SOFT MATTER PHYSICS 2013; 87:053012. [PMID: 23767625 DOI: 10.1103/physreve.87.053012] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/03/2013] [Indexed: 06/02/2023]
Abstract
In this paper we examine the anisotropic slip theory for gas flows based on tangential accommodation coefficients and compare it with molecular dynamics (MD) results. A special gas-wall boundary condition is employed within MD simulations to mimic the anisotropic gas-wall collision mechanism. Results from MD simulations with different surface orientations show good agreement with the slip quantification proposed in this work.
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Affiliation(s)
- Thanh Tung Pham
- Laboratoire Modelisation et Simulation Multi Echelle UMR 8208 CNRS, Universite Paris-Est, 5 Boulevard Descartes, 77454 Marne-la-Vallee, Cedex 2, France
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Asmolov ES, Schmieschek S, Harting J, Vinogradova OI. Flow past superhydrophobic surfaces with cosine variation in local slip length. PHYSICAL REVIEW. E, STATISTICAL, NONLINEAR, AND SOFT MATTER PHYSICS 2013; 87:023005. [PMID: 23496608 DOI: 10.1103/physreve.87.023005] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/08/2012] [Indexed: 06/01/2023]
Abstract
Anisotropic superhydrophobic surfaces have the potential to greatly reduce drag and enhance mixing phenomena in microfluidic devices. Recent work has focused mostly on cases of superhydrophobic stripes. Here, we analyze a relevant situation of cosine variation of the local slip length. We derive approximate formulas for maximal (longitudinal) and minimal (transverse) directional effective slip lengths that are in good agreement with the exact numerical solution and lattice-Boltzmann simulations. Compared to the case of superhydrophobic stripes, the cosine texture can provide a very large effective slip. However, the difference between eigenvalues of the slip-length tensor is smaller, indicating that the flow is less anisotropic.
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Affiliation(s)
- Evgeny S Asmolov
- A.N. Frumkin Institute of Physical Chemistry and Electrochemistry, Russian Academy of Sciences, 31 Leninsky Prospect, 119071 Moscow, Russia
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Pham TT, To QD, Lauriat G, Léonard C, Hoang VV. Effects of surface morphology and anisotropy on the tangential-momentum accommodation coefficient between Pt(100) and Ar. PHYSICAL REVIEW. E, STATISTICAL, NONLINEAR, AND SOFT MATTER PHYSICS 2012; 86:051201. [PMID: 23214772 DOI: 10.1103/physreve.86.051201] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/09/2012] [Indexed: 06/01/2023]
Abstract
In this paper, we study the influence of platinum (100) surface morphology on the tangential-momentum accommodation coefficient with argon using a molecular dynamics method. The coefficient is computed directly by beaming Ar atoms onto the surfaces and measuring the relative momentum changes. The wall is maintained at a constant temperature and its interaction with the gas atoms is governed by the Kulginov potential. To capture correctly the surface effect of the walls and the atoms' trajectories, the quantum Sutton-Chen multibody potential is employed between the Pt atoms. The effects of wall surface morphology, incident direction, and temperature are considered in this work and provide full information on the gas-wall interaction.
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Affiliation(s)
- Thanh Tung Pham
- Laboratoire Modelisation et Simulation Multi Echelle, Université Paris-Est, UMR 8208 CNRS, 5 Boulevard Descartes, 77454 Marne-la-Vallée Cedex 2, France
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Vinogradova OI, Dubov AL. Superhydrophobic Textures for Microfluidics. MENDELEEV COMMUNICATIONS 2012. [DOI: 10.1016/j.mencom.2012.09.001] [Citation(s) in RCA: 95] [Impact Index Per Article: 7.9] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/27/2022]
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20
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Priezjev NV. Interfacial friction between semiflexible polymers and crystalline surfaces. J Chem Phys 2012; 136:224702. [DOI: 10.1063/1.4728106] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022] Open
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Zhou J, Belyaev AV, Schmid F, Vinogradova OI. Anisotropic flow in striped superhydrophobic channels. J Chem Phys 2012; 136:194706. [DOI: 10.1063/1.4718834] [Citation(s) in RCA: 32] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022] Open
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