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http://hdl.handle.net/2445/187803
Title: | Experiments on perturbed Saffman-Taylor flows |
Author: | Ignés i Mullol, Jordi |
Director/Tutor: | Maher, J. V. Ortín, Jordi, 1959- |
Keywords: | Dinàmica de fluids Pertorbació (Dinàmica quàntica) Fluid dynamics Perturbation (Quantum dynamics) |
Issue Date: | 26-Jun-1997 |
Publisher: | Universitat de Barcelona |
Abstract: | [eng] We have performed pattern formation experiments where a relatively well understood system (flow in a Hele-Shaw cell) is perturbed either by means of a lattice of grooves or by the use of viscoelastic fluids. We have extended the qualitative analysis found in the literature for anisotropic fingering patterns, presenting a more quantitative approach that may prove useful as a tool to attack more complex problems. We have analyzed the different morphological regimes and looked for signatures of the transition between phases, with partial success when we try to characterize a given morphology quantitatively. In our studies of viscoelastic Hele-Shaw flow with associative polymer solutions, we have observed a transition from viscous fingering patterns into a regime where the growing patterns resemble the fracture in brittle solids. We have been able to rescale the threshold for these transitions, and we have observed interesting properties in a regime of fracturelike patterns where, under sorne circumstances, we have measured a characteristic oscillation frequency which shows interesting regularities. We have also studied the pressure in the viscoelastic flow, and found consistent results that may be used to implement a better theoretical model to fully understand the dynamics. |
URI: | http://hdl.handle.net/2445/187803 |
Appears in Collections: | Tesis Doctorals - Departament - Estructura i Constituents de la Matèria |
Files in This Item:
File | Description | Size | Format | |
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JIM_PhD_THESIS.pdf | 16.66 MB | Adobe PDF | View/Open |
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