Aspects of low Reynolds number microswimming using singularity methods

<p>Three different models, relating to the study of microswimmers immersed in a low Reynolds number fluid, are presented. The underlying, mathematical concepts employed in each are developed using singularity methods of Stokes flow.</p> <p>The first topic concerns the motility of an a...

Πλήρης περιγραφή

Λεπτομέρειες βιβλιογραφικής εγγραφής
Κύριος συγγραφέας: Curtis, M
Άλλοι συγγραφείς: Gaffney, E
Μορφή: Thesis
Γλώσσα:English
Έκδοση: 2013
Θέματα:
_version_ 1826315699820167168
author Curtis, M
author2 Gaffney, E
author_facet Gaffney, E
Curtis, M
author_sort Curtis, M
collection OXFORD
description <p>Three different models, relating to the study of microswimmers immersed in a low Reynolds number fluid, are presented. The underlying, mathematical concepts employed in each are developed using singularity methods of Stokes flow.</p> <p>The first topic concerns the motility of an artificial, three-sphere microswimmer with prescribed, non-reciprocal, internal forces. The swimmer progresses through a low Reynolds number, nonlinear, viscoelastic medium. The model developed illustrates that the presence of the viscoelastic rheology, when compared to a Newtonian environment, increases both the net displacement and swimming efficiency of the microswimmer.</p> <p>The second area concerns biological microswimming, modelling a sperm cell with a hyperactive waveform (vigorous, asymmetric beating), bound to the epithelial walls of the female, reproductive tract. Using resistive-force theory, the model concludes that, for certain regions in parameter space, hyperactivated sperm cells can induce mechanical forces that pull the cell away from the wall binding. This appears to occur via the regulation of the beat amplitude, wavenumber and beat asymmetry.</p> <p>The next topic presents a novel generalisation of slender-body theory that is capable of calculating the approximate flow field around a long, thin, slender body with circular cross sections that vary arbitrarily in radius along a curvilinear centre-line. New, permissible, slender-body shapes include a tapered flagellum and those with ribbed, wave-like structures.</p> <p>Finally, the detailed analytics of the generalised, slender-body theory are exploited to develop a numerical implementation capable of simulating a wider range of slender-body geometries compared to previous studies in the field.</p>
first_indexed 2024-03-06T19:02:03Z
format Thesis
id oxford-uuid:13dcb39b-f5b7-4d46-92d4-21a9afbecd08
institution University of Oxford
language English
last_indexed 2024-12-09T03:30:50Z
publishDate 2013
record_format dspace
spelling oxford-uuid:13dcb39b-f5b7-4d46-92d4-21a9afbecd082024-12-01T14:12:03ZAspects of low Reynolds number microswimming using singularity methodsThesishttp://purl.org/coar/resource_type/c_db06uuid:13dcb39b-f5b7-4d46-92d4-21a9afbecd08Fluid mechanics (mathematics)Mathematical biologyEnglishOxford University Research Archive - Valet2013Curtis, MGaffney, E<p>Three different models, relating to the study of microswimmers immersed in a low Reynolds number fluid, are presented. The underlying, mathematical concepts employed in each are developed using singularity methods of Stokes flow.</p> <p>The first topic concerns the motility of an artificial, three-sphere microswimmer with prescribed, non-reciprocal, internal forces. The swimmer progresses through a low Reynolds number, nonlinear, viscoelastic medium. The model developed illustrates that the presence of the viscoelastic rheology, when compared to a Newtonian environment, increases both the net displacement and swimming efficiency of the microswimmer.</p> <p>The second area concerns biological microswimming, modelling a sperm cell with a hyperactive waveform (vigorous, asymmetric beating), bound to the epithelial walls of the female, reproductive tract. Using resistive-force theory, the model concludes that, for certain regions in parameter space, hyperactivated sperm cells can induce mechanical forces that pull the cell away from the wall binding. This appears to occur via the regulation of the beat amplitude, wavenumber and beat asymmetry.</p> <p>The next topic presents a novel generalisation of slender-body theory that is capable of calculating the approximate flow field around a long, thin, slender body with circular cross sections that vary arbitrarily in radius along a curvilinear centre-line. New, permissible, slender-body shapes include a tapered flagellum and those with ribbed, wave-like structures.</p> <p>Finally, the detailed analytics of the generalised, slender-body theory are exploited to develop a numerical implementation capable of simulating a wider range of slender-body geometries compared to previous studies in the field.</p>
spellingShingle Fluid mechanics (mathematics)
Mathematical biology
Curtis, M
Aspects of low Reynolds number microswimming using singularity methods
title Aspects of low Reynolds number microswimming using singularity methods
title_full Aspects of low Reynolds number microswimming using singularity methods
title_fullStr Aspects of low Reynolds number microswimming using singularity methods
title_full_unstemmed Aspects of low Reynolds number microswimming using singularity methods
title_short Aspects of low Reynolds number microswimming using singularity methods
title_sort aspects of low reynolds number microswimming using singularity methods
topic Fluid mechanics (mathematics)
Mathematical biology
work_keys_str_mv AT curtism aspectsoflowreynoldsnumbermicroswimmingusingsingularitymethods