Hydrodynamic interactions : microswimmers near boundaries
department or school: Applied Science, Faculty of
department or school: Mechanical Engineering, Department of
data provider: DSpace
degree campus: UBCV
creator: Abtahi, Seyed Arman
issued: 2022-12-22T21:15:09Z
issued: 2022
related degree: Doctor of Philosophy - PhD
degree grantor: University of British Columbia
description: Both biological swimming microorganisms and artificial active particles capable of propulsion have recently been active areas of research in fluid dynamics. The influence of nearby boundaries or other active particles or swimmers is critical in many important cases for understanding various phenomena. Bacteria, for example, accumulate near surfaces and interact closely to form biofilms. Accordingly, this dissertation addresses a few gaps in the literature of microorganism hydrodynamics. First, we focus on the suspension of active particles near solid boundaries. We start with the study of the hydrodynamics of two unequal swimmers at close proximity by considering the squirming model. In comparison to passive particles, microorganisms have surface activity that provides the impetus for swimmers to move. In order to satisfy both the boundary conditions on the swimmers' skin and the Stokes equations, a regular perturbation in the velocity and pressure field of the inner creeping flow between the swimmers is employed. A relatively large size ratio leads to the hydrodynamics of a squirmer near a flat surface. Afterwards, we calculate the far-field hydrodynamics of a suspension of squirmers near a solid boundary. In the course of calculations, an extension of Stokesian Dynamics (SD) method, developed for passive particles, is utilized for active particles. This technique, called active SD, offers a good starting point for further research questions in the field. The transition between near-field and far-field solutions is also discussed. Thereafter, we propose a rigid and a flexible toy model to examine the effect of elasticity on the dynamics of a swimmer. Eventually, the developed method can help to establish a relation between hydrodynamics and biological behaviours, e.g., biofilm formation. Ultimately, we focus on axisymmetric particles in non-Newtonian fluids as a first step toward extending the SD method for poly disperse nonspherical active particles in complex flu…
aggregated CHO: https://circle.library.ubc.ca/rest/handle/2429/83480
note: Hydrodynamic interactions:microswimmers near boundariesbySeyed Arman AbtahiB.Sc., Isfahan University of Technology, 2014M.Sc., Western University, 2017A THESIS SUBMITTED IN PARTIAL FULFILLMENT OFTHE REQUIREMENTS FOR THE DEGREE OFDOCTOR OF PHILOSOPHYinTHE FACULTY OF GRADUATE AND POSTDOCTORAL STUDIES(Mechanical Engineering)THE UNIVERSITY OF BRITISH COLUMBIA(Vancouver)December 2022© Seyed Arman Abtahi 2022The following individuals certify that they have read, and recommend to the Fac-ulty of Graduate and Postdoctoral Studies for acceptance, the dissertation entitled:submitted by in partial fulfillment of the requirements forthe degree ofinExamining Committee:Additional Supervisory Committee Members:iiHydrodynamic interactions: microswimmers near boundariesSeyed Arman AbtahiDoctor of PhilosophyMechanical EngineeringGwynn J. Elfring, Associate Professor, Mechanical Engineering, UBCSupervisorNeil J. Balmforth, Professor, Mathematics, UBCSupervisory Committee Member Brian Wetton, Professor, Mathematics, UBCUniversity ExaminerMiranda Holmes-Cerfon, Associate Professor, Mathematics, UBCUniversity ExaminerHenry Fu, Associate Professor, Mechanical Engineering, The University of UtahExternal ExaminerCarl Ollivier-Gooch, Professor, Mechanical Engineering, UBCSupervisory Committee MemberSupervisory Committee MemberKendal Bushe, Associate Professor, Mechanical Engineering, UBCAbstractBoth biological swimming microorganisms and artificial active particles capableof propulsion have recently been active areas of research in fluid dynamics. Theinfluence of nearby boundaries or other active particles or swimmers is critical inmany important cases for understanding various phenomena. Bacteria, for exam-ple, accumulate near surfaces and interact closely to form biofilms. Accordingly,this dissertation addresses a few gaps in the literature of microorganism hydrody-namics. First, we focus on the suspension of active particles near solid boundaries.We start with the study of the hydrodynami…
has type: Thesis/Dissertation
date issued: 2023-05
is shown at: 10.14288/1.0422832
language: eng
degree discipline: Mechanical Engineering
provider: Vancouver : University of British Columbia Library
publisher: University of British Columbia
rights: Attribution-NonCommercial-NoDerivatives 4.0 International
rights URI: http://creativecommons.org/licenses/by-nc-nd/4.0/
scholar level: Graduate
contributor: Elfring, Gwynn
type: Text
identifier URI: http://hdl.handle.net/2429/83480