The Characterization of Common Cardiovascular Flow Regimes Using Newtonian and Non-Newtonian Fluids
| atmire.migration.oldid | 1144 | |
| dc.contributor.advisor | Rival, David | |
| dc.contributor.advisor | Johnston, Clifton | |
| dc.contributor.author | Walker, Andrew | |
| dc.date.accessioned | 2013-07-15T21:14:04Z | |
| dc.date.available | 2013-11-12T08:00:16Z | |
| dc.date.issued | 2013-07-15 | |
| dc.date.submitted | 2013 | en |
| dc.description.abstract | This thesis consists of three projects with the enveloping theme devoted to the characterization of common cardiovascular flow regimes using Newtonian and non-Newtonian fluids. The viscous behaviour of hydroxyethyl starch (HES) fluids available in Canada to treat hypovolemia remains unknown. The first project characterized the viscosity of these fluids using capillary viscometry and pressure drop measurements. The viscosities of HES 130/0.4 (Voluven®, Volulyte®) and HES 260/0.45 (Pentaspan®) were less than and greater than blood respectively. HES 130/0.4 (Voluven®) at 100% concentration unexpectedly displayed shear thickening behaviour at high flow rates. HES fluids were subsequently diluted in a blood analog fluid of aqueous xanthan gum. As expected, both HES 130/0.4 fluids decreased the analog viscosity while HES 260/0.45 increased analog viscosity and no evidence of previous shear thickening was found. Variability in viscous behaviour suggests changes in the molecular composition between batches. The non-Newtonian behaviour of blood is often ignored in cardiovascular flow modelling. To address the importance of non-linear rheology, flow patterns were experimentally measured using Newtonian and non-Newtonian blood analog fluids in separated flow environments. Flow induced by a Gianturco Z-stent showed that Newtonian assumptions underestimated wall shear stress (WSS) while expanding recirculation and oscillatory shear. This suggested that linear viscous assumptions overestimated the risk of intimal hyperplasia. In transitional flow induced by a stenosis, the non-Newtonian fluid extended laminar flow behaviour while damping turbulent shear stress. Conversely, the Newtonian fluid displayed downstream shear layer break-up and a radial expansion in elevated turbulent shear stress at the distal end of the field of view at peak pulsatile flow. Translation to the measurement of separated flow in vivo requires imaging in opaque environments. Echo particle image velocimetry (Echo PIV) has presented itself as an attractive tool; however, application to stenotic flows has been minimal. Echo PIV measured centerline velocities showed a good fit to PIV; however, failure to accurately resolve near wall flow patterns suggested further refinement is necessary prior to its use as a reliable quantitative imaging tool in such environments. | en_US |
| dc.identifier.citation | Walker, A. (2013). The Characterization of Common Cardiovascular Flow Regimes Using Newtonian and Non-Newtonian Fluids (Doctoral thesis, University of Calgary, Calgary, Canada). Retrieved from https://prism.ucalgary.ca. doi:10.11575/PRISM/28029 | en_US |
| dc.identifier.doi | http://dx.doi.org/10.11575/PRISM/28029 | |
| dc.identifier.uri | http://hdl.handle.net/11023/823 | |
| dc.language.iso | eng | |
| dc.publisher.faculty | Engineering | |
| dc.publisher.faculty | Graduate Studies | |
| dc.publisher.institution | University of Calgary | en |
| dc.publisher.place | Calgary | en |
| dc.rights | University of Calgary graduate students retain copyright ownership and moral rights for their thesis. You may use this material in any way that is permitted by the Copyright Act or through licensing that has been assigned to the document. For uses that are not allowable under copyright legislation or licensing, you are required to seek permission. | |
| dc.subject | Engineering--Biomedical | |
| dc.subject.classification | hydroxyethyl starch | en_US |
| dc.subject.classification | Newtonian fluid | en_US |
| dc.subject.classification | non-Newtonian fluid | en_US |
| dc.subject.classification | Particle Image Velocimetry | en_US |
| dc.subject.classification | echo particle image velocimetry | en_US |
| dc.subject.classification | transitional flow | en_US |
| dc.subject.classification | flow separation | en_US |
| dc.subject.classification | Wall Shear Stress | en_US |
| dc.title | The Characterization of Common Cardiovascular Flow Regimes Using Newtonian and Non-Newtonian Fluids | |
| dc.type | doctoral thesis | |
| thesis.degree.discipline | Biomedical Engineering | |
| thesis.degree.grantor | University of Calgary | |
| thesis.degree.name | Doctor of Philosophy (PhD) | |
| ucalgary.item.requestcopy | true |