Global ETD Search
Search theses and dissertations gathered from participating repositories worldwide. Every result links back to the library that holds it. No account is needed.
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Showing 1 to 20 of 21 for “"contact lines"”.
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Finite-element simulations of interfacial flows with moving contact lines
… framework for interfacial flows with moving contact lines. In our method, the contact line is advected naturally by the flow field. Contact angle hysteresis can be easily implemented without explicit calculation of the contact angle or the contact line velocity, and meshindependent results …
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Moving contact lines, wetting transitions and interfacial instabilities in confined environments
… on the nanometer scale in the vicinity of contact lines, where fluid phases meet the surrounding solid surface, to the micrometer scale of the confinement in a pore or microfluidic device, and finally to kilometer scale of the natural geologic phenomena. The multi-scale nature of immiscible …
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Methods for the direct simulation of nanoscale film breakup and contact angles
… simulation of fluids with free surfaces and contact lines, with a focus on capturing nanoscale physics in a continuum based computational framework. Free surfaces and contact lines have long presented some of the most challenging problems in computational fluid dynamics. Extensive progress …
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Ion Irradiation Induced Roughening and Smoothing of Metal Films on Dielectric Substrates
… in situ TEM. Due to line tension in the curved contact lines during local melting, irradiation induced dewetting occurs much slower than dewetting under homogeneous heating. At high irradiation doses, nanopattern disappear to form nanoparticles with decreased surface roughness. The particles …
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Droplet deposition on hydrophobic surfaces for agricultural sprays
… we create sparse pinning sites that pin the contact lines of the impacting droplets from the spray and prevent them from bouncing off. We first study the behavior of the impact of two droplets containing oppositely charged polyelectrolytes on a hydrophobic surface. We then study the …
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An interferometric study of spreading liquid films
Moving contact line problems involving polymeric materials and other complex fluids are encountered in many applications such as coating flows, gravity-driven drainage, and spin-coating operations. Viscous, capillary, inertial and gravitational forces can all be important in these flows depending …
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FLOW FORMING OF CAPILLARY INTERFACES: DROP IMPACT AND THE MOBILE CONTACT LINE
… into fast-time scale motion of the three-phase contact-line (CL). The CL then comes to rest and the LG interface oscillates, viscously dissipating remaining energy on a slow-time scale. The energetics of drop deposition are characterized by high Reynolds number and moderate Weber number. …
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Thin fluid films subject to external airflows
… for the ridge to de-pin at one or both of its contact lines. Secondly, we describe the possible pinning and subsequent de-pinning of a thin rivulet with constant nonzero contact angle as well as the possible de-pinning and subsequent re-pinning of a thin rivulet with constant width as they flow …
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Development of an Immersed Boundary Method for the Simulation of Moving Bodies at Fluid-fluid Interfaces
… to include the effects of surface tension and contact lines are presented. A detailed description of the numerical methods, as well as their implementation into a new software framework, are presented. Details regarding the solution of the resulting large systems of sparse equations in parallel …
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Computational Modeling of Droplet Impact Dynamics on Solid Substrates
… this project revolves around modeling the moving contact lines at the interface in a multiphase flow environment. Focusing on research from an aircraft de-icing point of view, this study is considered a prerequisite in understanding the physics of droplet impact. The primary focus is on extending …
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Interfacial Fluid Dynamics in Porous Media
… Part II by revisiting the theory of moving contact lines over heterogeneous surfaces and rationalizing the transition from stick-slip to steady sliding. The physical problems we investigate in this dissertation may prove helpful in addressing our current environmental challenges by inspiring …
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Phase-field modeling of liquids splitting between separating surfaces and its application to high-resolution roll-based printing technologies
… interfaces, topology changes, and slipping contact lines. In the phase-field simulations described in this study, the liquid ink transport between the rollers is approximated as the stretching and splitting of liquid bridges with pinned or moving contact lines between vertically separating …
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Influencing contact-line behavior in dynamic wetting through thermocapillarity and surface topography
… air to coat a moving substrate. A three-phase contact line is present wherever the solid surface, and the advancing and receding fluids intersect. Controlling the behavior of contact lines is key to improving the efficiency of industrial processes. The work in this thesis focuses on developing …
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Fluctuations, Phase Separation and Wetting Films near Liquid-Gas Critical Point
… present quantitative results about the receding contact lines. It is found that the vapor recoil force is responsible for the receding contact line. Local density fluctuations were observed by illuminating a cylindrical cell filled with the pure fluid near its liquid- gas critical point and …
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The numerical simulation of thin film flow over heterogeneous substrates
… manner subject to a specific error tolerance. Contact lines are ubiquitous in the context of droplet spreading and the wellknown singularity which occurs there is alleviated by means of a disjoining pressure model. The latter allows prescription of a local equilibrium contact angle and three …
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Hybrid atomistic-continuum formulations and the moving contact line problem
… technique is subsequently applied to the moving contact line problem. The motion of contact lines (the locus of intersection of a two-fluid interface with a bounding solid) has, due to the multitude of length scales involved, been one of the few problems that has defied theoretical analysis over …
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Specialized Inter-Particle Interaction Lbm For Patterned Superhydrophobic Surfaces
… nano/micro roughness can manipulate the droplet contact angle, thus providing an opportunity to control the droplet wetting characteristics. The Shan and Chen (SC) lattice Boltzmann model (LBM) is a good numerical tool, which holds strong potentials to qualify for simulating droplets wettability. …
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Fluid-fluid displacement in porous-media microfluidics
… model to simulate two-phase flow with moving contact lines in the partial wetting regime. We construct a self-consistent formulation of fluid-solid surface energy which allows prescribing arbitrary static contact angles. We then propose a formulation to account for nonequilibrium conditions …
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Mean-Field Free-Energy Lattice Boltzmann Method for Liquid-Vapor Interfacial Flows
… the three typical theories or laws for moving contact lines, and liquid-vapor channel flows. Third, proper scaling laws are derived to represent the physical system in the framework of the LBM. For the first time, to the best of the author's knowledge, we obtain a flow regime map for …
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Quantifying microbubble streaming and its applications
… presence of viscous boundary layers and pinned contact lines at the walls (i) strongly couples volume oscillations of the bubble to shape oscillations of the interface, and (ii) results in much wider surface-mode frequency resonance peaks than is nominally predicted by potential flow theory. The …
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