Fluid Mechanics for Biomedical Applications: Weakly Viscoelastic Electrospray, Flow Focusing and Collapsible Channel Models

Three different research topics are discussed in this thesis: i) weakly-viscoelastic electrospray, ii) the emergence of whipping effect on the Flow Focusing technique, and iii) fluid-structure interaction (FSI) phenomena implementing a 2D collapsible channel model. i) A systematic, theoretical comparison of a Newtonian fluid, and a non-Newtonian one modelled using an Oldroyd-B model was performed, resulting in a better understanding of how the properties of this type of material influence aspects such as meniscus shrinking, the agreement with a 1D-slenderness model, or the minimum flow rate value defining the boundary between electrospray and electrospinning. ii) In order to use Flow Focusing for some applications (e.g. XFEL), chaotic oscillations on the jet, known as whipping, must be avoided. A stability map for axisymmetric and lateral perturbation modes was obtained and compared to previous experimental data, examining the effect of different nozzle geometries on the emergence of the whipping effect and jetting-to-dripping configuration physical boundary. iii) In the last paper, the implemented model overcame some limitations presented in other 2D collapsible channel models, leading to analysis using a non-negligible membrane thickness and large deformations on the flexible wall segment. The multiplicity of solutions and their folding points, and the quantification of the effect of physical parameters such as wall thickness and inertia values on the emergence of self-excited oscillations were investigated.

Author dc:creator

• Blanco Trejo, Sergio

Advisors dc:contributor.advisor

• Gañán-Calvo, Alfonso M.
• Herrada Gutiérrez, Miguel Ángel

Statement dc:rights

• Attribution-NonCommercial-NoDerivatives 4.0 Internacional

Licence dc:rights.uri

• http://creativecommons.org/licenses/by-nc-nd/4.0/

Language dc:language.iso

eng

Handle dc:identifier.uri

https://hdl.handle.net/11441/139050

OAI identifier oai:identifier

oai:idus.us.es:11441/139050