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 52 for “"superhydrophobic surfaces"”.
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Experimental studies of liquid marbles and superhydrophobic surfaces
… of water droplets with hydrophobic or rough, superhydrophobic solid surfaces has been studied. Such surfaces may be found in the natural world and their potential applications range from waterproof and self-cleaning surfaces to droplet microfluidics. A measure of hydrophobicity is obtained …
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Specialized Inter-Particle Interaction Lbm For Patterned Superhydrophobic Surfaces
… INTER-PARTICLE INTERACTION LBM FOR PATTERNED SUPERHYDROPHOBIC SURFACES</p> <p>by</p> <p>AMAL S. YAGUB</p> <p>ABSTRACT:</p> <p> Superhydrophobic surface characteristics are important in many industrial applications, ranging from the textile to the military. It was observed that surfaces …
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Enhanced Laminar Convective Heat Transfer using Microstructured Superhydrophobic Surfaces
… One such example is a micropatterned, superhydrophobic surface, which has been shown to enable slip resulting in a decrease in drag and pressure loss for both laminar and turbulent flow. The hydrodynamic effects of these surfaces have been studied in depth, but the effects on heat …
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Droplet behavior on superhydrophobic surfaces: Interfaces, interactions, and transport
… dynamics on smooth hydrophobic and textured superhydrophobic surfaces, and to understand the dependence of interfacial interaction mechanisms on surface morphology. ^ A detailed understanding of the dynamics of droplet response to an applied electric field is essential for implementation of …
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The influence of superhydrophobic surfaces on near-wall turbulence
Superhydrophobic surfaces are able to entrap gas pockets in-between surface roughness elements when submerged in water. These entrapped gas pockets give these surfaces the potential to reduce drag due to the overlying flow being able to locally slip over the gas pockets, resulting in a mean slip at …
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Characterization of the robustness of superhydrophobic surfaces during condensation
… power plants in their power generation cycles. Superhydrophobic surfaces can potentially improve the heat transfer due to condensation when compared to the untreated surfaces typically used in condensers. This can improve the efficiency of power plants by up to 3%. These surfaces are made by …
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Skin friction drag reduction in turbulent flows using superhydrophobic surfaces
The use of randomly textured superhydrophobic surfaces have recently gained interest as a potential approach for the passive reduction of skinfriction on the hull of ships, submarines and underwater projectiles. When submerged in water, these surfaces trap a layer of air (or 'plastron') within …
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Numerical Prediction of Drag Reduction and Interfacial Shapes Over Superhydrophobic Surfaces
… developed to study the drag-reducing effects of superhydrophobicity for realistic surfaces. A multiphase Navier--Stokes volume-of-fluid based approach is developed to investigate the effect of interface curvature, and turbulence on drag reduction in the presence of realistic roughness. A Gibbs …
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Heat transfer through a condensate droplet on hydrophobic and nanostructured superhydrophobic surfaces
… governing vapor condensation on non-wetting surfaces is crucial to a wide range of energy and water applications. In this thesis, we reconcile classical droplet growth modeling barriers by utilizing two-dimensional axisymmetric numerical simulations to study individual droplet heat transfer …
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A comprehensive model of electric-field-enhanced jumping-droplet condensation on superhydrophobic surfaces
Superhydrophobic micro/nanostructured surfaces for dropwise condensation have recently received significant attention due to their potential to enhance heat transfer performance by shedding positively charged water droplets via coalescence-induced droplet jumping at length scales below the …
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Passive and active approaches to sustained turbulent hydrodynamic drag reduction using superhydrophobic surfaces
Superhydrophobic surfaces have been shown to trap a pocket of air (or a "plastron") in between the features of their rough texture when submerged in water. A partial slip condition is created at the interface between the water and the submerged body, allowing for a reduction in skin friction drag. …
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Droplet growth kinetics on superhydrophobic surfaces and future work on combating cryogenic surface contamination
… smaller droplets during dropwise condensation on superhydrophobic aluminum surfaces. In large systems, neglecting this influence is less of a concern as the error will largely be contained in the uncertainty of the heat transfer rate prediction. However, in smaller phase-change heat transfer …
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Evaporative cooling via jumping droplet condensation on superhydrophobic surfaces for localized car air conditioning
… cooling via jumping droplet condensation on superhydrophobic surfaces to provide localized cooling with 100 times less power input. Jumping droplet condensation takes place when microscale droplets coalesce on superhydrophobic surfaces and excess surface energy is converted to kinetic energy, …
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Wetting hysteresis and droplet roll off behavior on superhydrophobic surfaces by Katherine Marie Smyth.
… when water droplets are deposited on micro-post surfaces of different post densities. Hysteresis is commonly defined as the difference between the advancing and receding contact angle and after many decades of research, the mechanisms governing hysteresis are still not fully understood. …
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Droplet levitation and underwater plastron restoration using aerophilic surface textures
… of active components in liquids and responsive surfaces to resist the wetting of water on solid surface textures. When a superhydrophobic surface comes into contact with water, it traps a thin layer of air (plastron) within its surface texture. This entrapped air is advantageous for reducing the …
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Investigations on Multiscale Fractal-textured Superhydrophobic and Solar Selective Coatings
… a fractal model to describe wettability on such surfaces. These surfaces are described with a fractal asperity model based on the Weierstrass-Mandelbrot function. Using this description, a model is presented to evaluate the apparent contact angle in different wetting regimes. Experimental …
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Condensation heat transfer on nanoengineered surfaces
… Due to their remarkably low droplet adhesion, superhydrophobic surfaces were investigated for application to dropwise condensation. Although precise model superhydrophobic surfaces were necessary to gain insight into these phenomena, it was recognized that wide-scale implementation necessitates …
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Simulating the Motion of Droplets on High-Slip Patterned Surfaces
The leaves of many plants are superhydrophobic due to micro- and nano-scale structures on their surfaces, a property that may have evolved to clean the leaves by encouraging water droplets to bead up and roll off. Patterned superhydrophobic surfaces can also exhibit reduced friction, and liquids …
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Nanostructured electrospun fibers : from superhydrophobicity to block copolymer self-assembly
… into two areas. The first part is related to superhydrophobic or "self-cleaning" surfaces. This has been a hot research area due to the wide applications of such materials. Electrospun fibers were first discovered in this dissertation to have sufficient surface roughness for superhydrophobic …
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Hydrophobic nanostructured glass surfaces using metal dewetting process
… in contact angles exceeding 150 degrees. Superhydrophobic surfaces were made with the addition of a secondary roughness feature and the a PDMS coating.
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