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 “"Hele-Shaw cell"”.
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Bubble scavenging in Hele-Shaw cell
… carried out for bubble scavenging in a gap, or Hele-Shaw cell, for various gap distances. A novel approach was developed to measure the particles collected by a single bubble by allowing the bubbles to pop and transport these particles to a glass plate where they can be counted. The experiments …
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Viscous Fingering Instability of Complex Fluids in a Radial Hele-Shaw Cell
… involving complex fluids in a radial Hele-Shaw is investigated. Many fluids in our lives such as shaving foams, glues, flour-water dough, mayonnaise, and paints are complex fluids which exhibit multiple non-Newtonian properties simultaneously such as shear-thinning or shear-thickening, …
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Reduced-dimension model for the Rayleigh-Taylor instability in a Hele-Shaw cell
In this thesis we present a reduced-dimension model for the density-driven hydrodynamic Rayleigh-Taylor instability. We motivate the project with experimental findings of a little-understood stabilizing effect of geometry and deviations of measured instability wavelength from theoretical …
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Ferrofluid dynamics in a Hele-Shaw cell simultaneously stressed by DC and rotating magnetic fields
… in biomedicine. Careful measurements in Hele-Shaw cells with simultaneous perpendicular DC and in-plane rotating magnetic fields have shown that ferrofluid drop spiral patterns rotate in the same direction as the rotating magnetic field, independent of the polarity of the perpendicular DC …
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Mechanics of seed-grown planar chemical gardens
… gardens studied in confined geometries -- Hele-Shaw cells and microfluidic chips -- is presented. Studies in these geometries have been classified into three approaches: seed-growth in Hele-Shaw cells, injection-growth in Hele-Shaw cells, and co-injection-growth in microfluidic chips. Over …
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Viscous fingering instabilities and gravity currents.–—
… fluid either in a porous medium or in a Hele-Shaw cell, which is commonly referred to as the Saffman–Taylor instability. There are three related problems studied in this thesis: a single-layer viscous gravity current spreading from a point source over a rigid surface, radial spreading of …
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Mixing with complex patterns : from the impact of miscible viscous fingering to the effects of motile bacteria
… viscous fingering has on mixing. We use a radial Hele-Shaw cell as an analog of radial flows in porous media, and high-resolution fluorescent imaging, to measure the temporal and spatial evolution of the mixing zone. We identify distinct regimes in both the interface length and average thickness …
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Ferrofluid surface and volume flows in uniform rotating magnetic fields
… surface driven flows, spin-up flows, and Hele-Shaw cell flows and instabilities. To characterize the water-based and oil-based ferrofluids used in experiments, measurements were made of the magnetization curve, surface tension, viscosity, density, and the speed of sound. Extensive …
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Self-assembled Precipitation Membranes and the Implications for Natural Sciences
… where flow is forced by a pump and others in a Hele-Shaw cell where the flow is driven by the membrane itself. In the first, with externally forced flow, the growth of a wavy precipitate membrane is observed. We establish that its growth is controlled by transverse diffusion and dispersion of …
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Experimental Investigations on Flow and Mass Transport in Stressed Rough Fractures
… thesis I introduce a novel pressure-controlled Hele-Shaw cell to investigate different physical processes in rough fractures using 3D-printed rock analogs. This system can measure high-resolution fracture aperture and tracer concentration maps under relevant field stress conditions. Using a …
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Magnetic fluid flow phenomena in DC and rotating magnetic fields
… two glass plates separated by a small gap (Hele-Shaw cell) and excited by an applied uniform rotating magnetic field first and then a DC axial magnetic field, a phase like transition occurs that transforms the ferrofluid drop from a continuous phase to a discrete phase. Considering the …
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Pattern formation in fluid injection into dense granular media
… solutions, utilizing a novel setup based on a Hele-Shaw cell filled with dense dry sand. The two dimensional nature of the setup allows direct visualization and imaging analysis of the real-time fluid and grain kinematics. The experimental results reveal that the fluid flow patterns show a …
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Interfaces in disordered media. Scaling growth, avalanche dynamics, and microfluidic fronts
… in fluid systems, ranging from the macroscopic Hele-Shaw cell to a microchannel.
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Colloidal phoretic motion
… results of dried silica and latex films. A Hele-Shaw cell experiment measured the flux of latex particles down a concentration gradient of silica particles. The latex motion was arrested by increasing salt concentration, consistent with electrolyte diffusiophoresis driven by silica and its …
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Understanding the evolution of miscible viscous fingering patterns
… recovery and groundwater remediation. We use a Hele-Shaw cell to study experimentally how changing three parameters the injection rate, the viscosity contrast between the two fluids, and the gap thickness through which the fluid flows -- affects the resulting fingering pattern. The results lead …
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The Impact of Surface Modified Nanoparticles on the Performance of Polymer Solutions for Heavy Oil Recovery
… polymer solutions (nanopolymer sols) are, nevertheless, an emerging class of materials. A more structured approach is needed to properly understand the physical and chemical interactions between the NPs and the polymer solutions. In the first stage of this study, nanopolymer sols were prepared by …
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Moving contact lines, wetting transitions and interfacial instabilities in confined environments
… less wetting and more viscous liquid in a radial Hele-Shaw cell (two plates separated by a small gap). We show that the wetting liquid invades the cell in the form of a thin-film front, which becomes unstable and leads to a viscous fingering pattern. To gain an understanding of the front dynamics, …
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Dynamics of confined chemical gardens and implications for submarine methane hydrates
… contact with solutions such as sodium silicate. Hele-Shaw cells, quasi-two-dimensional micro reactors, can be used to reduce the complexity of the system: osmosis is removed when performed with injection, and buoyancy if placed horizontally; the results are thus only dependent on the relationship …
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Controlling Viscous Fingering
… of a greater viscosity in a porous medium or a Hele-Shaw cell. Linear stability analysis is used to predict methods of suppressing instability. Then, experiments in which nonlinear growth dominates pattern formation are analysed to explore the nonlinear impact of strategies of suppressing finger …
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Aspects of Parity Breaking in Classical and Quantum Fluids
… probes of parity breaking effects, namely the Hele-Shaw cell. We also explore how these effects may manifest in a ferrofluid. In the second half of this thesis we move to quantum systems, beginning with the fractional quantum Hall effect. Starting with a microscopic theory of electrons in an …
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